how does a edlebrock 600 sound for a 78 trans am 400cid? will this work or should i go bigger or a differend brand? :confused:

depens if its bone stock yer in good shape but if you have head work and or a big cam the car is trying to breath better so a bigger carb will let it but not to big tryed a 1250 domminator with all the trimmins on a 383 small block nova and it would just dump gas out the headers (this was just a way to show a friend a little over kill cuz he had a simmilar question

edelbrock carbs are garbage.. holley fer sure.. or demon

The very best carb for the car came on the car. Have the Q-Jet rebuilt by a competent Q-Jet man, and you will never need another carb. Ignore the hype about "Quadra-Junk" and "Quadra-Flood". Those are sour grapes fom people trying to do something they simply don't understand.
Cliff's Q-Jets in Ohio can modify tht 800 Q-Jet to support well over 500 horsepower. Q-Jets have the unique design of the tiny primaries and huge secondaries. This makes for good response at low engine speed, and plenty of volume for high-end. Carter imitated it with ThermoQuad.
Most prosfessional carb guys report significant tuning issues with the E-clones of the Carter carbs. The E-Q-Jet, however, has shown to be versitile and effective. Price is HIGH...
If you're dead-set against Q-Jet (for whatever reason), Holley is the only good alternative. The 3310 would be first choice, but an adapter is required, and adapters are not recommended.
BTW, 600 CFM isn't nearly enough for a 400 Pontiac. 750, minimum, unless you're using small valve heads, and trying to make all your power under 4,500. (Don't laugh, I have customers with 400s in pickups, and that's EXACTLY what they want)
Check out Jim Hand's book "How to Build Max-performance Pontiac V8s" by SA Designs. You will find tons of good and CURRENT information on carbs and cams, intakes and headers, without all the mythology and superstition found at the hobby level today.
Also, check out

boyleworks.com (click on muscle cars)
classicalpontiac.com
performanceyears.com

These sites all have excellent Q&A sessions for Pontiac-specific inbformation (real Pontiac, not corporate Pontiac).

Would the Edelbrock 600 get good fuel economy then? It may be that he is looking for a daily driver in todays high gas price situation.

Anyone know where I can buy a rebuilt Q-Jet, the carb on my 77 is most nearly gone.

Go to boyleworks.com and click on muscle cars. Then, go to the restoration and performance forum. There's a recent post there from Jim Hand, that has a link to Cliff's Q-Jets. The title of the thread refers to the "book".

i used a edelbrock 750 on my sbc and have had no problems. easy to adjust, simple and basic. i would go with the 600 for a stock daily driver.

Opinions on Holley vs Edelbrock vs Q-Jet are just like GM vs Ford. Everyone has their own...
Having said that, I really like the Edelbrock 600 I'm currently running. It actually gained me about 1.5--2 mpg on the highway too. I've used Q-jets (and 4 jets, remember those?) in the past with good luck also, but didn't seem to perform for as long as my Ebrock. Holley fans, I guess I've always had lemons, owned two and not a big fan. I have friends who believe a Holley is the only carb made. Gotta love it.
Most overcarburate. If your 400 is stock, or near stock, 600 CFM is more than adequate.

I look up Cliffs Q-Jet and they really didnt have much to offer, but http://www.customrebuiltcarbs.com/ has a wide selection of carbs, including Q-Jets, they do rebuilds or even build you a custom carb, so take a look over there everyone.

The 600 is an economy carb and a pile IMHO. With your car being mostly stock and you wanting good milage, I concure with Mr Pbody. Cliff knows q-jets like no one else. I am a holley guy myself but dont expect good gas milage. The Q-jet has very small primaries which are great on the milage and when the secondaries open, bammmm big gas sucking secondaries. You can try your luck at Schucks but you may end up trying 3 or 4 to get one that works right!!!

Get a quadrajet that has been rebuilt by holley.They are pretty good unless they get exposed to dirty fuel.Where quadrajets may all look the same,they come in so many configurations that you have to be very specific when you pick them out.Too lean,you might burn up a piston.Too rich your just stinking up the place and fowling out plugs.A properly jetted Carter AFB competition carb mixes pretty well.And they dont loose adjustment like your holley designs have been caught doin.its like set it and leave it.They come with an automatic choke that is preset.Its easy to take it off and run a cable choke.

I got a reman Q jet a few years ago , The shaft fell off the side with the choke linkage . I like Edelbrock myself . Had two , rebuilt and rejetted one for a friend in an hour . Bout to buy a performer package kit for a 4.3 chevy. Rob

i got a '79 TA with a 400c.i. the 600cfm edelbrock lets it run but it is not near the amount of air that big block takes in so it whistles and cuts way back on power now i run a 750cfm A LOT MORE POWER. Although i am running a few mods

Ive noticed more than a couple posts on various threads about a "big block" 400...is there a big block and a small block or are people just saying "big" in that it is a rather latge small block engine? Just curious cause I always thought the 6.6 400 Pontiac was a small block engine.

The 6.6L 400 Pontiac is a big block motor along with th 6.6L 403 oldsmobile, but the chevy 400 is a small block build on the same format as the chevy 350. Some manufactures made the 400 a big block because the factory or any chevy 400 small block is weak and unreliable even with a block filler. so with a big block 400 it has more metal in the cylinder walls and can be bored over with ease where as the 400 chevy is pretty well stretched to the max. this is why i laugh when people tell me they have a factory chevy 400 bored .060 over. No offense to the 400 chevy guys out there.

As for Q-Jets vs. Holley vs. E-carbs, well, maybe there are many opinions, but among those that do it every day, Q-Jet gets the nod for a street car, and Holley for racing. The Edelbrock Q-Jets are quite good, but configured for use in Chevys.
Cliff's Q-Jets doesn't have many carbs in stock, true. Send him YOURS! He's the author of many a 500-plus horsepower motor with a Q-Jet.
Pontiac engines are not big blocks. They are not small blocks. They are Pontiacs. Period. We affectionately refer to them as the "Injun Engine" (with all due respect to the "native" American they are named for). There is a "small journal" (a relative term, as the small journal is 3", and larger than any Chevy) and large journal. Deck height, bore spacing, cam/crank relationship are all the same, unless you throw in the bastardized 265/301 (which none of us will admit is really a Pontiac).

i have to agree about the carbs and the 265-301 engines are , well, there.

i dont know many racers who run holley.Most have gone with injection,or a carter AFB comp or edelbrock performer.A lot of old restored 454's and 455's are sporting q-jets tho.And nobody says they dont have a race car,cause they so darn fast.And when you put them to the test they have very respectable and consistent trap times.

And hey i saw a 283 with a tunnel ram,taking down big blocks at thunder valley.He was spinning it up to like 9krpm's.On top of the tunel ram = plural q-jet carbs,synchronized.I have a picture here somwhere of him outrunning a 426 hemi to the end of the track,and the hemi could lift both front tires off the ground.

you can build these small blocks to do anything as lomg as the mods are availiable. the 69 302 z28 motor is a 390 hp beast. its built to rev high rpms. id love to have one of those but i cant find one

make your own
isnt a 302 =a 327 bore with a 283 crankshaft?

you know the small block chevy is probably the most universal engine out there just because all of the engines that they based off its format you can swap parts on any small chevy to make almost any other small chavy without doing machine work i'll set up a link with a parts swap list from chevy to show what i mean it even has specs on different c.i. small block chevys

There is no Big or Small Pontiac block. All blocks are the same externally.

There is no Big or Small Pontiac block. All blocks are the same externally.


funny thing the 78 trans am i used to own had a 400 big block, also all of the other trans ams/firebirds i see in car shows are big blocks too.

now the 3rd gens are small blocks, and 87 was the last year they dropped a pontiac block into a trans am. from 88 up they are chevy blocks.

funny thing the 78 trans am i used to own had a 400 big block, also all of the other trans ams/firebirds i see in car shows are big blocks too.

now the 3rd gens are small blocks, and 87 was the last year they dropped a pontiac block into a trans am. from 88 up they are chevy blocks.

You did not have a big block 400. If it was a Pontiac block it is refered as a Pontiac block. The external size dictates big and small blocks. The big block Pontiac is just a misconception in Pontiacs. The 326-350-389-400-421-428-455 are all the same size. The big differece is the main journal size. The 326-350-389-400 share the same size main journal of 3" and the 421-428-455 share the 3 1/4" journal. Most people would not know this but it would be the best way to describe a Pontiac." Big journal or Small Journal". All connecting rods in all pontiacs are the same size. 6.625 long . The difference in all these engines were Bore and stroke.

i was doin measurements on my 76 with my dad, and the 400 pontiac in it right now is the same width as a big block, ill save 2 inches er so on each side if i put in a sbc 350

My third gen is soon to be a 400PO,instead of a SBC.I plan on tuning it up to 500 foot pounds of torque,maybe closer to 600,depending on what cam and intake i put on my 6x's.My car only weighs 3200 right now.It might be kinda quick.

Where pontiacs v-8's are seemingly the same casting,the length of the rods,throw of the crankshaft,and diameter of the pistons are what make its total displacement.But what really sets them apart,is the thickness of the water jacket.

You cannot turn a 350 pontiac block into a 455.And as most of us know,the bearing diameter isnt such a big deal if you have a good machinist.But even the best machinists cant make up for the fact that if you bore out a 350 block to fit a 455 piston,your getting so close to the water works of the engine,that a cracked block or warped cylinder is almost unavoidable.

The same can be said about boring a 283 up to a 400.It can be done but it sure as heck gonna burn up.Not enough steel to drill on.

To sum it up,the bolt holes all line up,but each engine has a different thickness of the casting,so it isnt the same.And if it isnt the same then it must be different.

For a 400 CID engine the Ideal CFM @ 100% efficency is 750 CFM:

How to determin your maximum needed cfm:
(Engine Size (c.i.d.) X Maximum rpm) / 3,456 = cfm @ 100 percent Volumetric Efficiency (VE)

(400 x 6,500) / 3,456 = 752.3 CFM

you can rev a 400 Pontiac to 6500? I havn't driven mine yet since i put the 400 in it...just curious.

they sell cams rated that high...but i was wondering the same thing.I was wanting to run the 400 trans in mine too when i wedge it under my hood.But i would want to drill it down for extra clutches in first and second.400 trans run pretty good with a ten inch converter on em ..Does edelbrock sell a rev-limiter or traction control for cars with carbs?

This motor im installing is going to stick above my hood two and a half inches with the air cleaner on it.Guess its time to make a custom hood scoop.I wonder if edelbrock sells vaccume pods that could quickly open and close a custom hood scoop.

you could always put one of those gay wanna be blower air cleaners on there with the butterflies...

haha good old birdcatchers... they look pretty neat though... well at least the ones i seen up close... sittin on a blown 327

yea, but that car was actually blown...I'm talkign about the fake ones that are just air cleaners but are supposed to look like a blower.

yea i get what you mean

well i was thinking somthing closer to a raised functional cowl induction of sorts..blower wasnt the best choice of words.

Yea functional cowl's look pretty sharp.. my families 2 chevelles have them

the parts to a chevelle cowl system are expensive,i looked it up in the jegs catalog at work.I was hoping to rig up my own for cheaper.i cant see spending over 200 bucks for somthing so simple.I wanted a shaker style hood,but the motor is way too high for all that.

Are you running a high rise intake or whats the intake setup on your motor... i think the shaker hook is the look to stick with to bad it doesnt fit

well im putting a 1972 pontiac 400 into a 1982 Firebird.Its looking like a aluminum edelbrock torker intake is going on it,and a carter AFB or maybe a holley or q-jet is going to be its carb.
I,know its going to be higher than my 1970 chevelle 350 thats currently in it,and the 350 with a torkerII intake hits the hood somtimes.Without any air cleaner at all.

hmm.. tough break...im actually downsizin my 76 400 to a 69-80' 350 chev.. i wanna run and edelbrock performer airgap with either a demon or holley on top so i think i should be good fer clearance on that one

I estimate the overall heith of the motor under hood is going to raise two inches.I was thinking of building some kind of custom power bulge with a cowl built in,and making it out sheet metal,instead of fiberglass.Once its done i will rivet it right to my hood,with a rubber seal in between.Then i dont have to worry about a bunch of fiberglass breaking on my hood,and looking like crap

yea ive seen somebody in town here do something similar to that on his 79 camaro.. doesnt look bad at all

why u downsizing?

well im downsizing first because the 400 is gettin kinda tired, second i hope to lighten it up a bit, and third ill be gettin more power out of the 350 if all goes well

Do you have any other pic's of ur car you could send... liek some different angles?

the 350 chevy is heavier i think.And you will get more HP,but you will not have as much torque.Ive done about all i can for my chevy 350,and a pontiac 400 still has more power,period.My 350 dont play around at all not to be bragging,but im moving up to a 400 pontiac motor,for the extra torque.

hmm.. good to know man thx

check out my gallery.I just put some crappy pictures of my Crown vics new set of 255-60-15's on back.I have a lot of pictures of my car inside and out,as well as pictures of some of my other cars

how do i check the gallery?

nm i got it

click the gallery button below my car on this post and it will take you to it

dont get excited my car is a POS thats been through a lot.the body is in bad shape,i just ripped the exhaust pipe clean off the passenger side collector.Really its junk but im proud of it cause its been through hell and back.

k well i gotta jet man nice talkin to yah

right on.Have fun on the forum getting to know everyone.Some pretty cool people on here,some really know there stuff too.

yea thanks man.. im only 15 so im just startin out so all the help and knowledge i can get is just awsome

Yes you are correct in saying that the castings internally are thicker for boring purposes just as an early 455 has thicker castings than a later one. But the way one says Big Block or small block is based on external size as in Fords and Chevy's. Pontiacs externally are all the same so that would mean that they are just one dimension. I have been into Pontiacs for over 30 years and have heard the term Big block once in a while thrown out and the ones that throw it out say. Boy I could tell it was a big block by its size! Well then all Pontiacs are Big blocks and there would be no small block sooooooooooo you cannot differenciate by calling it a big block when there is no small block. I have right now 4 Pontiacs. 3 1968 Birds, a Convertible 400 4 sp that I show,a 400 auto that I race and drive on the street. It does 12.60 on ARCO gas and does a 0-60 ft in 1.67 seconds with a 0-60mph in under 3.8 seconds. This is with a stock 400 with non ported heads.I also have a 1968 Bird with 530,000 miles on it and is my daily driven 400. The 4th one is an 1989 GTA Convertible 350. I have also owned a 1967 400 4 speed Bird, a 1969400 4 sp Bird, a 1978 TA and a 1968 GTO 400 4sp. I have a 350, 2-400s, 2 428s and 4-455s sitting in my garage. I do know my Pontiacs so I will not go any more into this subject since it is is what it is and just be forwarned, do not go onto any other true Classic Pontiac site and say that you have a big block or a small block since you will hear the same answer I am giving you. PS I also have a BIG BLOCK 454 Vette convert and a 350 small block in my truck and a BIG BLOCK 460 in my motor home. My other cars are true PONCHO Power. Not big block or small block.

cool man thats an awsome stack of parts you have.

Hey if you been around pontiacs that long,i was wondering about the 6x heads.i notice they have some pretty big valves.But what is a step up from that.They have to be over 2 inches,just by looking.My boss has a 1970 GTO judge motor for sale.Its a rusty block and a set of heads with 6x on em.The crankshaft is freshly ground ready for install,but the block needs punched up to 040,and it needs a few bolt extractions.Are those heads worth 300?They are buildable.Would it give a 72 catalina engine more power,or could the catalina engine already have the same heads?

2.11 intake 1.66 exhaust. The compression will be 8-1 if they are 6X#8s, or if you have the 6X#4s you will have 8.2. The chamber of the 6X#8s have 101 cc and the 6X#4s have 93 cc. These are great heads for 455s but with 400s they dont have enough compression to put out real good performance. I would suggest trying to find some 16s or 62s or 12s, 13s and then your compression will be 10-1 and because Pontiacs are a flat top piston and the head chambers are fully machined you can run premium gas and get away without detonation.
http://img25.exs.cx/img25/4740/ResizeofP1020258.jpg
http://img25.exs.cx/img25/8063/Car20I20race20019.jpg

Right on.I was going to have the heads milled down to add some compression.How far down would be too extreme.Can i go with milling it 40-50 thousanths,and getting custom valve cutouts.Its not going to be a daily driver,i was going to keep a blend of sunoco gas in the tank.Sombody told me a stock intake polished is more than ample for power purposes.Should i buy a edelbrock torker,that i could get for 30 bucks?Cause i plan on camming it too.

Did the 70 judge come out with a steel crank?

Ive noticed more than a couple posts on various threads about a "big block" 400...is there a big block and a small block or are people just saying "big" in that it is a rather latge small block engine? Just curious cause I always thought the 6.6 400 Pontiac was a small block engine.

Ugh!!!!! There is no big or small block. Its actually an intermediate block but all Pontiac blocks are the same externally. So how about just being called Poncho Powered!!

edelbrock carbs are garbage.. holley fer sure.. or demon

LMAO.....I just bought a 1406 Edlebrock for my 74 chev truck and feel like I just pissed away 300 bucks. I came here wondering how to set it up. Like how many turns to back off the idle mixture screws from shut before I start the engine. (the instructions only tell you how to tune it and are rather vauge compared to the Holley set up and tuning manual).

Actually I bought it as a spare as I repair the Holley that just puked plus I have a trashed beater that needs a carb.

JohnnyL, welcome to the forums. Before posting, please check the dates of the topics before you post in them. This topic is over 2 years old. No need to resurrect it.