69' BOSS 302 VS Camaro Z28

Since they are both 302's I would like to know which would win in a race assuming same drivers and 4 speeds.
I know they are both rated at 290 HP.
IMO the Boss 302 would win. It just has to make more power than the chevy 302. The boss 302 has cleveland heads with HUGE (2.23/1.71)canted valves and gigantic ports. Chevy's 302 is just plain old 2.02/1.60 valves, not sure about the ports I assume better than most other SBC's.
I would like to know specs on these cars, like curb weights and gear ratios kind of stuff. Both were solid cams and 780 CFM holleys.

Well, I personally thing the '69 Z28 would of been the better contender of the two. In '69 the Mustang got a tad bigger and about 150lbs heavier.

The Z28 was rumored to have in the ballpark area of 360-400hp in reality. They weren't popular cause people thought they were slow, but you just had to shift them at like 7000rpm.

I'm not sure about the Ford version, I think it'd be a interesting race to say the least.


My money is on the Z28 though.

my money is on the z28 as well the boss was a "performance" engine but it still not on the same basis with the z28 engine. the z28 engine was oneof chevys major things! i have never heard of a boss mustang beating a z28 stock. my buddy has an i think its a 71 but don't hold me ot that z28 and one of the guys a tschool has a 66 boss 302 and they race out of the student parking lot ive been with him and the z28 steps out on the mustang every time. i don't know if the 302 is just beat or what but his z28 is stock.

my money is on the z28 as well the boss was a "performance" engine but it still not on the same basis with the z28 engine. the z28 engine was oneof chevys major things! i have never heard of a boss mustang beating a z28 stock. my buddy has an i think its a 71 but don't hold me ot that z28 and one of the guys a tschool has a 66 boss 302 and they race out of the student parking lot ive been with him and the z28 steps out on the mustang every time. i don't know if the 302 is just beat or what but his z28 is stock.
Well first of all the BOSS 302 was the second fastest mustang in the 60's right along side of the BOSS 429, so it's Fords major thing too.
Secondly there was no such thing as a boss 302 in 66. The 302 wasn't put in Mustangs until 67.5. Most 68's had the 302. So the 302 in that mustang isn't original. And the other thing is that 71 Z28 does not have a DZ302 like the 69 Z28 does. Totally different comparison. BTW a true 69 Z28 would annihilate that 71 Z28, and so would a 69 BOSS 302 Mustang.

The Z28 was rumored to have in the ballpark area of 360-400hp in reality.
So was the BOSS 302.

Does anybody know what the curb weights are on these cars? I would really like to know.

BTW a true 69 Z28 would annihilate that 71 Z28, and so would a 69 BOSS 302 Mustang.


Well, I'm not so sure a '69 Z28 could totally whoop on a '71 Z28. Especially from a dig, I think the '71 has the advantage from a stop cause it's got the 350. But top end pull, i'll admit the '69 Z28 would probably walk on by.

But I can almost guarantee that the '71 Z28 would be quicker through the lights of the 1320ft sprint than the '69 Z28. The '69s were hard to launch cause of the 302's high power band. It's very similar to the Honda S2000 below 4000rpm they act like slugs from a stop. Reason why you don't see many 1st gen Z28s cause people thought there were slow due to the fact they couldn't launch them right.

The Mustangs had the same problem, on paper they looked pretty impressive but on the street they're dependance of high revs made them difficult to launch.

I can't get the attachment thing to work. oh well

Both of these cars were tough to launch - especially the Z28. Most drivers on the street just wouldn't shift at 7000 rpm like you were supposed to.

so whats the curb weight on these cars? which one handled better? which one had the better potential for handling? which car do you guys think looks better?

Stylingwise, I have always preferred the Camaro over the Mustang, but looks are very subjective. Either one is a good looking muscle car.

Either one is a good looking muscle car.
I agree.

Anyone else?

I think the boss 302 had about 395 hp. My vote goes to the boss, Mustangs may not be the fastest cars from the 60's but they sure were the most beautiful in my own opioion.

didn't the 69 z28 dominate trans am racing??

didn't the 69 z28 dominate trans am racing??
Read the last paragraph to this article I found in one of my books. In 68' the Z28 dominated, but in 69(when the boss came out) they were less dominent in the Trans am racing. The Boss only won 4 out of 12 races, with the Z28 winning the other 8. From 66-70 ford won in 66, 67, and 70. Chevy won in 68-69, dominent in 68 and still winning in 69 but not so dominent.
http://files.automotiveforums.com/gallery/showphoto.php?photo=1746&size=big&password=&sort=1&cat=503

Anyone familiar with the Z-28 Can Am pacakge? It was a cross ram intake with 2 4-barrel carbs, high compression angle plug heads, factory headers and a chambered exhaust.
Only about 220 cars were sold with this very rare option package that wasnt listed in any of the official documentation, and was technically sold as a dealer installed option package from the parts counter.
Modern day dyno tests of Z/28s show the "base" ones to make around 375-400hp and the Can-Am equiped cars make about 460hp. Smokey Yunick supposedly created 6 expirimental Z's with hemi-style heads and some other goodies that were putting out over 500hp from the DZ302 motor.
In short, I think a Z would totally smoke a Boss 302.
The cars also had Muncie M-21 transmissions, "The Rock Crusher," with square cut gears and such, built for racing, and hard shifts. In fact, these transmissions were so tough, using clutch was more or less optional.
I also happen to know someone who owned a Can-Am equipped 69 Z and said the Boss was no competition. They said that the car was so powerful you could run it up to 8,000rpm in first (and you were doing almost 50mph) and yank it back into second, and the car would jump almost a full lane sideway from the toruqe if you werent careful.
I honestly cant verify this story (I wasnt even alive in 1969) but its from someone I trust.
I think the real downfall of the Z was the fact that it was a small displacement, high-revving motor in a time when people only understood cubes and low-end torque. Its funny now how my generation is building all these 4 cylinder screamers. I guess the DZ302 was just a motor 30 years ahead of its time. Imagine what could be done now a-days to a 302 with deep-breating 4 valve heads, fuel injection, and all those other goodies? Think a 9000rpm 240hp Honda 2 liter in the S2000 is impressive? Imagine a 9000rpm 600hp Chevy 5 liter. I wish someone would bring back the real Z....

Definitely one of the reasons the high winding small block 302 sold less than the big block 396s (and 350s) was that on the street, they required a lot of careful shifting and high reving. That definitely was ahead of its time.

In short, I think a Z would totally smoke a Boss 302.


If that was true the Boss would have never one any trans am races, but it did.

And no camaro owner is ever going to say they lost to a mustang, vice versa too.

And no camaro owner is ever going to say they lost to a mustang, vice versa too.


I would. :icon16:

Since they are both 302's I would like to know which would win in a race assuming same drivers and 4 speeds.
I know they are both rated at 290 HP.
IMO the Boss 302 would win. It just has to make more power than the chevy 302. The boss 302 has cleveland heads with HUGE (2.23/1.71)canted valves and gigantic ports. Chevy's 302 is just plain old 2.02/1.60 valves, not sure about the ports I assume better than most other SBC's.
I would like to know specs on these cars, like curb weights and gear ratios kind of stuff. Both were solid cams and 780 CFM holleys.
I've beat meny boss mustangs.

Allow me to expound on the head thing, the 2.02/160 heads have redesigned ports for better flow, and of course the bigger valves allow better breathing. The idea behind the larger valve is to flow better at high rpms, and thereby making more power, and in flow tests it does work. But I used to own a Z/28 with the 302 in it and I never lost to a boss mustang be it a 302 or a 429, I really think it boils down to how well the driver knows his car.

If that was true the Boss would have never one any trans am races, but it did.

And no camaro owner is ever going to say they lost to a mustang, vice versa too.
Just the facts

I would admit to losing, that is the one thing that makes us build on our Muscle cars and make them faster, I did lose to a 1970 Buick GS StageIII, GSX, and to a Baracuda with a 440 and then another one with a 426 Hemi, oh and an L-88 Vette. But never to a Boss mustang.

I'm thinking the Mustang must weigh more then, anybody have curb weight specs?

Well, I'm an old guy who was around in the late '60's and early '70's. I spent some great days at a 1/4 mi. track in Nashville (long gone now). My best friend had a '69 Z28 that he ran. I never saw a Boss 302 beat him. Guys, it's about the combination. The Boss 302's didn't run worth a crap off the showroom floor! The valves were far too big.

And actually the Z28's didn't run that good stock either. At the very least they required headers, dist. recurved, and carb. rejetted. Oh, and 4.56 gears, or at least 4.11's ( which meant you had to change rearends for any road trips).

My buddies Z28 won a lot of races -- and he still talks about how fast it was. But if you want to know the truth -- IT ONLY GOT INTO THE HIGH 13's A COUPLE OF TIMES!! Mostly it ran low 14's. That was with 4.11 gears, open headers, dist. recurved, and carb. rejetted. On street tires -- with slicks it ran slower because it bogged bad off the line.

The claims of big HP numbers are DREAMS! Only the baddest of the big blocks from that era can run with some of the new cars like SS Camaros or C5 Corvettes. Oh yeah, they could be made to run with mods, but with some of the right mods the new cars are faster still.

I know we always look back and think, "Oh the good old days when...". But those days weren't so good. Guys, THESE ARE THE GOOD OLD DAYS!! Modern muscle is way ahead of classic muscle in every way! :2cents:

i dont care, personally i would take a 1970 cuda...

:smile: Yeah, I always liked them too!

The Boss 302's didn't run worth a crap off the showroom floor! The valves were far too big.

This statement is correct, actually. The Cleveland head has huge ports at the end - which kills the airspeed and the horsepower. sure they flow alright for any engine with some decent mods to increase air speed, but aside from that they really wouldn't add that much. A mod done in australia is to fit aluminium square tubing to the inside of the heads to increase the air speed and get better horsepower, but this is considered extreme for a regular streetcar and is rarely done, many people fitting smaller 2V heads. When new alloy heads were made for the clevo, the exit ports were heavily revised.

That is an extremely hard question. But given the Z28s racing records I would have to go with it. Although I do not know much of the Boss 302, I do know they are very nice cars. I would love to own one, definately!

Well first of all the BOSS 302 was the second fastest mustang in the 60's right along side of the BOSS 429, so it's Fords major thing too.

Looking strictly at Magazine test times, neither the Boss 302 nor the Boss 429 was able to break into the 13's in stock street trim. With a 2.40:1 first gear ratio in the close ratio top-loader 4-speed transmissions, neither car was a pleasure to try and launch.
The 428 Mustangs on the other hand did, starting with the 428CJ in 1968.
Even the Ford specific magazines rated both the Boss 302 and 429's in the 14.0's.
Regarding the statements that were made suggesting that the Boss 302 made over 350HP in stock trim, that is just not true. The most optomistic estimates in the day were that the Boss 302 made 325HP in factory trim. The Boss 351 on the other hand, did in fact make over 350HP.
Going by the Magazine test times, the Z-28 had a best of 14.34 in Hot Rod Magazine. There was a test in Cars Magazine of a 69 Z/28 with a dual 4V Holley Cross Ram intake and 4.10 gears running a 13.75, but that can hardly be used as a fair stock comparison.
There were also magazine tests of "tweeked" Boss 429's in the low 13's and even into the 12's.

true, ford did ship tweaked mustangs to car testers to record their speeds. The Boss 351 was actually underrated, capable of making around 380hp with some modest tweaks. evidence is in the falcon GTHO which ran a similarly setup engine and is rumoured to make up to 400hp.

Dude go with the BOSS but get the 351. The old Z28s looked sweet but they don't match the BOSS which was built for racing.

Looking strictly at Magazine test times, neither the Boss 302 nor the Boss 429 was able to break into the 13's in stock street trim. With a 2.40:1 first gear ratio in the close ratio top-loader 4-speed transmissions, neither car was a pleasure to try and launch.
The 428 Mustangs on the other hand did, starting with the 428CJ in 1968.
Even the Ford specific magazines rated both the Boss 302 and 429's in the 14.0's.
Regarding the statements that were made suggesting that the Boss 302 made over 350HP in stock trim, that is just not true. The most optomistic estimates in the day were that the Boss 302 made 325HP in factory trim. The Boss 351 on the other hand, did in fact make over 350HP.
Going by the Magazine test times, the Z-28 had a best of 14.34 in Hot Rod Magazine. There was a test in Cars Magazine of a 69 Z/28 with a dual 4V Holley Cross Ram intake and 4.10 gears running a 13.75, but that can hardly be used as a fair stock comparison.
There were also magazine tests of "tweeked" Boss 429's in the low 13's and even into the 12's.

http://www.autofacts.ca/classics/fast.htm

http://www.musclecarclub.com/musclecars/general/musclecars-50fast.shtml

Both of these links show the BOSS 429 doing 13.6.
It is physically impossible that the boss 302 only made 325 HP. I would believe 325 ft/lbs of torque, but come on with cleveland heads and huge valves not to mention radical cams the 302's made 400 HP just like the 302 chevy's. I would believe the chevy made more torque , simply because of the flow characteristics (port velocity) of the Cleveland heads. They had 2.23/1.71 CANTED valves, larger ports than chevy's wedge heads which only had 2.02/1.60 valves. That much difference in valves alone is enough to be atleast 25 HP more, plus they are canted which aids flow. Both of these engines had similar solid lifter cams, an aluminum dual plane intake, and a 780 CFM Holley carb. What would give the edge in power to the chevy?

Both of these links show the BOSS 429 doing 13.6.
It is physically impossible that the boss 302 only made 325 HP. I would believe 325 ft/lbs of torque, but come on with cleveland heads and huge valves not to mention radical cams the 302's made 400 HP just like the 302 chevy's. What would give the edge in power to the chevy?

Both links quote the same source.....High Performance Cars. The test mule was tweeked.

I would not call the Boss 302 cam radical with only .477 in. lift at the valve, and 290 degrees duration.
Sure the duration is more than your average 302, but a 93 Mustang Cobra 5.0 motor has .477 lift.
The Boss 351 used nearly the same cam, and no one claims that it even made 400HP.
The Cleveland 4V heads are on the large side for a 302, and this cam is a compromise for the street. It would take alot more cam to get 400HP out of the Boss 302, although the heads are cpable of it.
Show me where it is documented that the street Chevy 302 made 400HP. I highly doubt it.

Both links quote the same source.....High Performance Cars. The test mule was tweeked.

I would not call the Boss 302 cam radical with only .477 in. lift at the valve, and 290 degrees duration.
Sure the duration is more than your average 302, but a 93 Mustang Cobra 5.0 motor has .477 lift.
The Boss 351 used nearly the same cam, and no one claims that it even made 400HP.
The Cleveland 4V heads are on the large side for a 302, and this cam is a compromise for the street. It would take alot more cam to get 400HP out of the Boss 302, although the heads are cpable of it.
Show me where it is documented that the street Chevy 302 made 400HP. I highly doubt it.

Can you prove it was tweeked?
290 duration doesn't mean anything, it's duration at .050 that counts. I don't know those specs.
The cobra 302 probably has a roller cam correct? Roller cams have MUCH more lift than any other cam and you cannot compare them.

HUH? The 351C in 71' probably made about 450 HP. It was faster than the BOSS 429 rated at 375, not to mention 450 ft/lbs. And the 351 was faster, HMM? The boss 351 had 11.7:1 compression, and you think all it made was the rated 330 HP? Please.
I've read lots of books that say although the 302 was rated at 290 HP, it was closer to 400 HP. But there was no torque of course.

OK found the specs of the factory boss 302 cam. 228 duration @.050'', .477 lift and 114 ICL. So you are right that it's not very radical, but still large for 302 cubic inches.
I plugged all the data into my desktop dyno with NO porting whatsoever, canted valves/stock ports-and with small tube headers open exhaust it came out 418 HP at 6500 RPM and 405 ft/lbs at 4500 RPM. With the small tube headers and mufflers options it comes out 393 HP at 6000 RPM, and 391 ft/lbs at 4500 RPM. Even with the ''high performance manifolds and mufflers'' option it comes out with 353 HP at 6000 RPM and 358 ft/lbs at 4500 RPM.
One other thing, for some reason these engines came with dual plane manifolds. With the small tube headers open exhaust option, and a single plane manifold selected it comes out to be 459 HP at 6500 RPM and 423 ft/lbs at 5000 RPM. Add pocket porting, and it comes out to 500 HP even. You don't need a huge cam to make big HP.

So, using the exact same cam ,I put in the 302 chevy specs. Wedge/stock ports and valves-202/160 valves, 11:1 compression small tube headers open exhaust and it show 371 HP at 5500 RPM and 393 ft/lbs at 5000 RPM. Smaller valves, no cant to the valves=less power even with more compression. Now of course I'm using the same cam, I'm not sure what the actual specs are for the chevy 302.

Even with the ''high performance manifolds and mufflers'' option it comes out with 353 HP at 6000 RPM and 358 ft/lbs at 4500 RPM.

Find an actual dyno test, not a cookie cutter desktop dyno guess.
Pull out some of the old magazine reviews and tests even.

Find an actual dyno test, not a cookie cutter desktop dyno guess.
Pull out some of the old magazine reviews and tests even.

Well the desktop dyno was pretty damn close to my actual dyno on my 273. Desktop dyno showed 321 HP, actual dyno showed 334 HP-but I had the runners smoothed and gasket matched-nothing else. The torque was off quite a bit though, it showed about 30 ft/lbs more than what it actually had.
Why don't you find the reviews? I know there is no possible way that this engine only made 325 HP. And the boss 351? LOL what a joke that it only makes 330. If it can eat the 429 for lunch, it MUST have well over 400 HP. Like I said the 429 was rated at 375 HP and 450 ft/lbs in 71'.

Find an actual dyno test, not a cookie cutter desktop dyno guess.
Pull out some of the old magazine reviews and tests even.

It's not really a guess, specs are specs. I know just about everything about these engines now, the only thing I didn't know before was the cam specs. Still don't know the chevy 302's. But if it is the same-
Here is the imput into desktop dyno:
69' 302 ford-4.002'' bore X 3'' stroke-301.9 CID
heads-canted valve/stock ports and valves
valve sizes-2.23 intake/1.71 exhaust
compression ratio-10.5:1
induction flow-780 CFM
intake manifold-dual plane
exhaust system-small tube headers open exhaust
camshaft-solid lifters, 228 duration @.050'', .477 lift, 114 ICL
peak HP-418@6500
peak torque-405@4500 RPM

69' Chevy 302:
4'' bore X 3'' stroke-301.6 CID
heads-wedge/stock ports and valves
valve sizes-2.02 intake/1.60 exhaust
compression ratio-11:1
induction flow-780 CFM
intake manifold-dual plane
exhaust-small tube headers open exhaust
cam-same as ford 302
peak HP-371 at 5500 RPM
peak torque-393 at 4500 RPM

71' BOSS 351C
4'' bore X 3.5'' stroke- 351.9 CID
heads-canted valves/stock ports and valves
valves sizes-2.19 intake/1.71 exhaust
compression ratio-11.7:1
induction flow-780 CFM(not sure about CFM, carb is Autolite 4300-A)
intake manifold-dual plane
exhuast-small tube headers open exhaust
cam-same
peak HP-440 at 5500 RPM
peak torque-466 at 4000-4500 RPM

I guess that the Desktop Dyno is a neat tool, but the hard facts are that even with open high flow headers, the Boss 351 did not make even 400HP and 400Lb-FT of torque, and the Boss 302 made less torque/horsepower than did the Boss 351.
When you are talking factory stock motors and parts, the cookie cutter guess (calculated estimation) of the Desktop Dyno software program is not always accurate. This is a case where it is off by a bunch.
The data you inputed does not differentiate between the factory iron Cleveland 4V heads of the Boss 302/352, and a head with specs like the Yates aluminum head which has smaller ports and valves than the 69 Boss 302 head, but makes it look like a 221 head in relative flow comparison.

True I would need actual flow bench data to punch in to be completely accurate.
However, I'll say this one more time-The BOSS 351 was FASTER than the boss 429 in 71'-the 429 was rated at 375 HP, engines were usually underrated. Plus the 429 has 450 ft/lbs of torque. Now, you think a 351 with less than 400 HP is going to beat the 375 HP 429? NO :banghead:

True I would need actual flow bench data to punch in to be completely accurate.
However, I'll say this one more time-The BOSS 351 was FASTER than the boss 429 in 71'-the 429 was rated at 375 HP, engines were usually underrated. Plus the 429 has 450 ft/lbs of torque. Now, you think a 351 with less than 400 HP is going to beat the 375 HP 429? NO

You do not get to the track much do you? For one thing, the Boss 429 was harder to launch because of the torque. 1/4 Mile ET does not always indicate absolute power when the car can not hook.
I'll say this one more time.............look at the real world, not your software and your guesses.

You do not get to the track much do you? For one thing, the Boss 429 was harder to launch because of the torque. 1/4 Mile ET does not always indicate absolute power when the car can not hook.
I'll say this one more time.............look at the real world, not your software and your guesses.

Well I watched a show on speed vision channel, I think it was Dream Car garage. They were talking about the 71' boss 429 mustang, but the one guy said the real sleeper was the boss 351 and it could ''eat the boss 429 for lunch''. Now I don't know if they were talking strictly at the track, but when I use those terms thats not what mean. I've never seen any boss mustangs run at the track myself, around here it's all them stupid 5.0 fox mustangs and 80's or ealry 90's F-body's. I actually like those cars, but everyone has one and i'm just sick of seeing them. Everybody always thinks their car is better and faster, blah blah blah :banghead:

Well I watched a show on speed vision channel, I think it was Dream Car garage. They were talking about the 71' boss 429 mustang, but the one guy said the real sleeper was the boss 351 and it could ''eat the boss 429 for lunch''. Now I don't know if they were talking strictly at the track, but when I use those terms thats not what mean. I've never seen any boss mustangs run at the track myself, around here it's all them stupid 5.0 fox mustangs and 80's or ealry 90's F-body's. I actually like those cars, but everyone has one and i'm just sick of seeing them. Everybody always thinks their car is better and faster, blah blah blah

They must have been talking about a '69 or '70 Boss 429, because there was no such animal in 1971. There was, however, the 429SCJ Mustang in 1971. This is one car that has not gotten enough credit in magazine reviews. The problem is that most of the reviews were either one legger CJ engines, 4 speed cars, or some combination of. There was only one test that I am aware of, that had a SCJ/Drag Pack car with an automatic. The automatic car was easier to launch, so naturally, you could get better times. The same thing is true for the Torino/Cyclone 429 cars. With the 2.40 first gear 4-speed, and the substantial weight of these cars, they were a bear to launch.
There are magazine tests for the 429SCJ Torino in the 13.60's range, and a 429SCJ Mustang even quicker. The Boss 351 had a best magazine time in the 13.80's.
The thing about a Boss 351 is that it only came with a 3.91 axle and the 2.78 1st geared wide ratio 4-speed. With over 200lbs less weight over the front tires, it was much easier to launch.
The 4-speed 428's fared better because it was a lighter engine in a lighter car, and the 428 with nearly a 4" stroke had a pile more low end grunt than did the 429 with its 3.59" stroke which was not far off of the 3.5" stroke of a Boss 351. The Boss 429 was designed for a Nascar oval, not street racing.
I have seen a pile of old Ford musclecars at both local tracks and at NMRA and World Ford Challenge races. I have personal experience with a 1970 429SCJ 4-speed Cyclone Spoiler.

They must have been talking about a '69 or '70 Boss 429, because there was no such animal in 1971. There was, however, the 429SCJ Mustang in 1971. This is one car that has not gotten enough credit in magazine reviews. The problem is that most of the reviews were either one legger CJ engines, 4 speed cars, or some combination of. There was only one test that I am aware of, that had a SCJ/Drag Pack car with an automatic. The automatic car was easier to launch, so naturally, you could get better times. The same thing is true for the Torino/Cyclone 429 cars. With the 2.40 first gear 4-speed, and the substantial weight of these cars, they were a bear to launch.
There are magazine tests for the 429SCJ Torino in the 13.60's range, and a 429SCJ Mustang even quicker. The Boss 351 had a best magazine time in the 13.80's.
The thing about a Boss 351 is that it only came with a 3.91 axle and the 2.78 1st geared wide ratio 4-speed. With over 200lbs less weight over the front tires, it was much easier to launch.
The 4-speed 428's fared better because it was a lighter engine in a lighter car, and the 428 with nearly a 4" stroke had a pile more low end grunt than did the 429 with its 3.59" stroke which was not far off of the 3.5" stroke of a Boss 351. The Boss 429 was designed for a Nascar oval, not street racing.
I have seen a pile of old Ford musclecars at both local tracks and at NMRA and World Ford Challenge races. I have personal experience with a 1970 429SCJ 4-speed Cyclone Spoiler.

Oh sorry I meant 429 super cobra jet, not boss. I get them mixed up because I was talking about the boss 351.
Anyway, I think I remember someone saying that 1/4 mile did not mean much. Oh that was you! Since the boss 351 came with 3.91 gears I would say it's pretty hard to get it to hook up too. The higher gears of the 429 make it easier to launch without spinning, what are you talking about?
Plus how do I know those times you gave aren't from ''tweeked'' cars?

The 4-speed 428's fared better because it was a lighter engine in a lighter car, and the 428 with nearly a 4" stroke had a pile more low end grunt than did the 429 with its 3.59" stroke which was not far off of the 3.5" stroke of a Boss 351.


:screwy:

A ''pile more low end grunt'' combined with a lighter car would make it MUCH harder to launch. Do you have any clue to what you are talking about?

A ''pile more low end grunt'' combined with a lighter car would make it MUCH harder to launch. Do you have any clue to what you are talking about?


I will give you a break. I can see that you haven't had much experience in the area of big block cars on limited traction.
When you launch on factory of smaller Drag Radials, you do not want to launch at a high RPM or you will overpower the tires. The 2.40 first gear ratio combined with a 3800-4000lb car is a prescription for bog when launching at a low RPM. It is a fine line between bog and lost traction without abusing your clutch every time. This is why automatic cars are easier to launch when talking about these animals.
Do yourself a favor and get out to the tracks where the old musclecars run. It is a blast to watch, and people are pretty friendly and easy to talk to as well as willing to discuss their cars.
I have been fortunate to have seat time in both newer "stupid 5.0's" and early small and big block muscle. I have had 351C powered early Mustangs and big block powered cars. Like I said already, I can talk abouty personal experience when launching an early 4-speed powered big block car. How about you?

To sum it up, the Boss 351 made more power than the Boss 302, and the 429SCJ made more power than did the Boss 351. Pretty simple concept. Bigger engine, more power. Especially when both Bosses used essentially the same heads.
You can't make horsepower without torque since horsepower is quite simply a function of torque and RPM. With less torque at the same RPM, the smaller engines make less horsepower. Basic stuff here.

To sum it up, the Boss 351 made more power than the Boss 302, and the 429SCJ made more power than did the Boss 351. Pretty simple concept. Bigger engine, more power. Especially when both Bosses used essentially the same heads.
You can't make horsepower without torque since horsepower is quite simply a function of torque and RPM. With less torque at the same RPM, the smaller engines make less horsepower. Basic stuff here.

You can make more HP with less torque, the simple fact of higher RPM...You know the basics.
A smaller displacement tends to rev higher in most cases, thus giving more HP. Like the desktop dyno showed, the 351 only made 20 more PEAK HP than the 302. But, of course at lower RPM.

Oh and the thing about launching-Well, I've only ever driver auto big blocks. 2 of them.
I did drive (as a daily driver) a 2wd pickup with a 383 stroker and 4:10 gears for 3 months. That had no traction whatsoever off the line. I ran a best of 13.1 on it with street tires. Could have been deep into 12's with slicks. That was about a year ago.

My computer can beat your computer..... :rofl:

My computer can beat your computer..... :rofl:

Probably :comprage1

What your Desktop Dyno does not show is that because of the factory Cleveland 4V head design, the heads work better on a 351 cube engine than a 302 cube engine, so with both using the same factory cam, there is more than a 20HP gap it their peak outputs.

What your Desktop Dyno does not show is that because of the factory Cleveland 4V head design, the heads work better on a 351 cube engine than a 302 cube engine, so with both using the same factory cam, there is more than a 20HP gap it their peak outputs.

Umm, no. The bore size is really the only thing that makes a head work different on a different engine. The bore sizes for the 302 and 351 are the same, 4''. Plus the heads are not the same, the boss 302 had 2.23 intake valves, helping the 302's peak HP output.

My point was the 302 will make good PEAK HP with the cleveland heads. Yes of course it will have no bottom end or throttle response.

Umm, no. The bore size is really the only thing that makes a head work different on a different engine. The bore sizes for the 302 and 351 are the same, 4''. Plus the heads are not the same, the boss 302 had 2.23 intake valves, helping the 302's peak HP output.

You are pretty clueless to Cleveland head based engines aren't you?
Don't even bring up the 69 Boss 302 heads which were too big for even the open track racing. No one used these heads when given a choice. The Boss 302 changed to the standard 351C 4V sized valves (2.19/1.71) for 1970. The hard core Cleveland drag racers did not even use these oversized valves.
Bore size effects valve shrouding.
Air volume and velocity effects head efficiency. This is the true difference between the 3.00 and 3.5" stroke engines.

My point was the 302 will make good PEAK HP with the cleveland heads. Yes of course it will have no bottom end or throttle response.

Peak HP is only good for bragging rights. Peak HP with no area under the curve does not win any competition of speed. Either way, the Boss 351 made more than 20HP greater than the Boss 302 did stock for stock.

Whatever, I don't fell like arguing anymore. Blah blah blah you win :loser:

Whatever, I don't fell like arguing anymore. Blah blah blah you win

Typical internet Cowboy type action.....hiding behind your cute little insulting smilies. Anything I typed to you , I would say in person. I don't hide behind a keyboard. Don't get whiney because I stand on my points. I never said that you couldn't make good power with Cleveland heads on a 302 cube engine, just that the Boss 302 as delivered from the factory is not an example of this, not that it didn't have potential.
A little history.....I took my drivers test in a 73 Mustang. The first engine I built was a 351C. That engine was in my 73 Mustang when I made my first of many passes down the 1320.
Tell me about your experience or at least of someone else's car that you saw run at the track, or that you talked to after they ran their car at the track. Don't hold the Desktop Dyno as the final authority on anything. It is a tool. Learn to use it and put it into a proper perspective.
Learn to debate like an adult, not a 16 year old kid who just got their license, reads magazines and hides behind a keyboard. Adults don't resort to direct insults when they do not like what someone else is saying.
If you don't want to discuss these motors anymore.....fine. If you do, then be civil.

I'm not getting whiny I'm just tired of your BS excuses. All you say is I don't know what I'm talking about, and thats all you are going to say to anything I throw at you so I'm done. :loser:

[QUOTE=PWMAN]I'm not getting whiny I'm just tired of your BS excuses. All you say is I don't know what I'm talking about, and thats all you are going to say to anything I throw at you QUOTE]

I made one statement that you are clueless when it comes to real world performance of the Cleveland head, and I stand by that. Just admit that you have no real world experience.
You have continued to refuse to address any of the technical points that I have brought up. You merely come back with something different, and continue with the insults.
You drift from the original points. Maybe you should stick to the boards where you can say whatever you want and people won't question you, you will have better luck.

I am open to discuss the Boss 302 and Boss 351/351 Cleveland engines, or any other Ford engine if you are man enough to do it without the childish insults.

Fine. So you rebuilt your 351 in your mustang, BFG-I bet it didn't even have 4 bbl heads. So because you rebuilt 1 cleveland, that makes you an expert?
I've rebuilt a 351M, 400M, 390 FE, 273 mopar, 350 chevy, 283 chevy. 383 stroker chevy, 307 chevy, 331 FE, 318 mopar, and soon a 360 mopar when I get the rebuild kit this week..probably more just cannot think.

I will admit that I have no experience with any clevelands, but plenty with modified's which is a whole different animal though.
But like I said before I have experience at the track, and launching cars that it's hard to get traction. Just no manuals, all auto's. We used to have a 67' GT vert mustang with 289 4 speed, drove it a few times but it was more like a show car and my dad would have killed me if I took it to the track. Even with the little 289, not to mention 3:1 airplane gears it would just spin through 2nd gear without much effort. Maybe if it had a posi...

Btw, there are things you didn't answer me about either so I don't want to here it.

Fine. So you rebuilt your 351 in your mustang, BFG-I bet it didn't even have 4 bbl heads. So because you rebuilt 1 cleveland, that makes you an expert?
I've rebuilt a 351M, 400M, 390 FE, 273 mopar, 350 chevy, 283 chevy. 383 stroker chevy, 307 chevy, 331 FE, 318 mopar, and soon a 360 mopar when I get the rebuild kit this week..probably more just cannot think.

I will admit that I have no experience with any clevelands, but plenty with modified's which is a whole different animal though.
But like I said before I have experience at the track, and launching cars that it's hard to get traction. Just no manuals, all auto's. We used to have a 67' GT vert mustang with 289 4 speed, drove it a few times but it was more like a show car and my dad would have killed me if I took it to the track. Even with the little 289, not to mention 3:1 airplane gears it would just spin through 2nd gear without much effort. Maybe if it had a posi...

Btw, there are things you didn't answer me about either so I don't want to here it.

This has degraded into silly chest thumping....I guess that I will digress one more time, and reserve my future responses to those things of a purely technical nature.
Well.....my friend......11 whole engines.........more than most internet "experts", but I have you more than covered. I not only have rebuilt many times more than you, including my share of Clevelands, I have run most of them on a dyno, although not the Clevelands. I never
claimed to be an expert or have all of the answers, I just refuted the points which you were attempting to make about how the Boss 302 made 400HP from the factory.
Not only have my many Cleveland engines had 4V heads, I still have several pair on the shelf for future projects. You admitted yourself that you have not even a single pair on any of your engines. Although that has nothing to do with you thinking that the Boss 302 was better than it really was.
By the way, leave the M off of the 400 Ford engine when you describe it, it doesn't belong. There has only been 1 400 Ford engine. The M only applies to the 351M. Just because someone puts a typo on a truck valve cover (351/400M), people think that there is a 400M engine.
You will find no reference in Ford literature including the master parts catalogs about a 400M, just the 400.
Your experience with 400 and M engines directly applies to 2V head applications. The heads do not know if they are on a 351M or a 351C. Other than the intakes, they are on an engine with a 4" bore and a 3.5" stroke. They are functioning the same. The disadvantage to the M is the weight.
This all started when you were defending the Boss 302 against the Z28, and made the statement that the Boss 302 was the second fastest Mustang. Magazine test times, and real world drag strip performances do not support this. You also couldn't believe that the Z28 made more power stock. With the dual ram intake, it most assuredly did. The 2.02 valve GM heads worked better on the Chevy 302 than did either of the oversized valve Boss heads.

If you are willing to try this again, let's keep this to technical info. Bring it on...........what questions did I not answer? If we continue with the stupid stuff, I am sure that the thread will get locked.

Well I wasn't thumping my chest, just trying to show you I have SOME experience under my belt.

anyway, about the 400M thing-you are right but everyone says it so I do too just out of habit. Don't make a BFG over it.

I will definitely admit that chevy's 302 made more low end power. And what are you talking about dual ram intake? The DZ302 had a single holley 4 bbl with 780 CFM.