Best heads for a 400?

us thats what i paid for it i not looking to make a profit
i will take a pic and send it to u ok

alright cool you want my email address ?

and that way you can send more info too

sure
i don't think it had an alt but everything else is there except the carb

alright well all Q-jets are 750 cfm so its fine about the carb

and i guess my 301 alt will fit hopfully

its [email protected]

mine did i think but if not there only like 40 bucks for a new one

yah thats fine

jut to let u know it needs alot of work it hasn't ran in over 5 years heads need to be redone i would just pull it apart and rebuild it that what i was gonna do and u can replace it with what u want. i did manage to turn it over and i was getting conpression out of it i bought it without knowing anything

yah thats what i was planning on doing

i don't remember if the intake was any good i think it was but i think one of the prongs for the carb got bent or something

i would be doing alot of work to it so basily everything would be replaced

peterguy, can u show me a 750cfm quadrajet?
possibly some GM stats please?

what you dont belive me on the cfm?

or what?

i didnt know they made 750 cfm rochester quadrajets, i was just curious to see if u had it documented?

i dont have it documented but i was told that all Q-jets are 750 cfm

im not sure 100% but i will look it up

i asked the owner of my shop and he told me they run about
650-680 cfm
i trust what he says cause his buisness is 40 years old so hes been around

yah well that seems about right but i mean they have to flow enough to feed a 455 but also a 301 but maybe they are all different

quadrajets are crap anyway, worst carburator ever made, i cant even give mine away no one wants it

Actually most q-jets are 750cfm. some early models, some late 70s BOP cars, and truck/rv ones were 795cfm.

well now thats kinda good to know but i thought over carbing an engine is bad so 750 cfm on a 301 that dosent seem to proper

would any of these heads 97,997,12,48,670,16,31,12,722,614 fit a 301 i highly doubt any would but do any?

also are 46 heads any good?

this site has made me happy knowing that i could make this power if the dyno is correct but is it????

here is the site http://www.pontiacwarriors.com/dyno/400/pontiac_400_dyno_runs.htm

also on that they use 6X heads

were there any small cc chamber 6X heads?

because if not ill just get my 6X heads on a 400 ported and then build up something similar to what the sites dyno thing says

found a site that might help you.
http://www.thepontiactransampage.com/compratio.html

no 46 heads are small valve heads 1.91/1.66 rather than 2.11/1.77

dose milling a set of heads reduce chamber size?

or just raise comp?

and im planning on keeping 6x heads but i would like to get a comp of 9.5-1.5:1 what could i do to get this?

Yes it increases compression and reduces chamber size. Some 6x heads are 101cc and others are 92cc. The most you can safely mill heads is .060 that is equivalent to about 15cc. So depending on the heads you have, after the milling they will be either 86cc which will be about 8.75:1 or 77cc which will be about 9.5:1.

alright cool what size chamber could i expect to have on one off a grand prix?

and how can i tell the difference if they have 101 or 92cc to start with?

grand prix ones should be 101cc

so i should be able to get it to a 8.75:1 comp with stock pistons?

and it would also be milled fully


but what are other ways to gain compression other then pistons or milling the heads?

that ratio is with flat top pistons, some 400s have dished.

alright so then should I put a set of pistons in it too or are the stock ones fine?

no way man, replace those pistons, get the best ones u can

yah i want to but the only set that i can find of after market pistons is ones that are 35 bucks a piece american

so i think thats around 500 can

which is steeeeeeeeep just for flat top forged

those are the pistons i bought for my engine, i know there expensive and the same ones for chevy are like $11 bucks its a rip off, but if u want the performance, go big or go home its the price u pay for building pontiac,
try to see if your seller will cut you a deal if u buy a rebuild kit all together

thats true i should get a rebuild kit anyway

so ill get a forged set in the rebuild kit

a rebuild kit can generally save you up to $500 bucks depending on the type of kit u got it, your going to need new gaskets if u re-build so mine as well just get the whole kit, get a .480 cam, flat top pistons, felpro gaskets ect ect ect, where i work i got to customize my kit but thats because i work there so mabey if u got sum connections u can make a custom re-build kit,
for example, my kit came with stock pistons and felpro gaskets so i changed my pistons to flat tops and upgraded the cam from stock to 4.80 lift just stuff like that i saved myself just under 400 bucks by buying it as a set vs buying everything seperate
now a chevy rebuild kit u can get for like 400 bucks CAN and thats like flat tops, huge cam felpro ect...this by the way is a small block rates, ide have to check on big blocks

well ive got my cam and all that other stuff picked out

and summit has a rebuild set with the flat tops for 470 usd

but that comes with everything like gaskets oil pump and so on

would a cam with a duration of 231/240 @ .050 with a lift of .517/.517
be street legal

what about 230/236 @ .050 and a lift of .488/.491

im in bc canada and the emissions laws are pretty tight i dont know any states to compare them to but anyhelp is apreciated

What year is the car? In the Texas most cars over 25 years old are exempt. But I don't know what its like in Canada.

in ontario its 20 years your exempt from emmissions,
a .517 cam would be good HP bad on gas and it would be a hard idler, a .488 would be wild enough but still let you idle

I am guessing that second cam is the xtreme energy. I would stay away from that one.

the .517 lift cam is basically for high high performance muscle cars or drag cars, if you want to be able to drive this on the street without going from gas station to gas station then get the .488 or even the cran cam, .440

quadrajets are crap anyway, worst carburetor ever made, i cant even give mine away no one wants it

Only to those who don't have the time or knowledge to work on them. For a street application there is almost no better carb when done up right. The problem comes because they are so much more advanced then a Holley (Common choice around here). A well-built Q-jet will perform quite well. If you must have a reference to this I have included one below (Though it is out of a rag). A major benefit of the Q-jet is its small primaries allowing for a great cold start and fairly decent gas mileage as long as you feather the pedal. How many carbed 350's can you cold start in minus 20oC? I can.

http://www.carcraft.com/howto/57178/index.html

Actually most q-jets are 750cfm. some early models, some late 70s BOP cars, and truck/rv ones were 795cfm.

750cfm until 1973 (I believe) then they became 800cfm (795cfm actual).

but what are other ways to gain compression other then pistons or milling the heads?

Domed Pistons are another way; thinner head gasket can also help. Increase the displacement also helps, on a 400 stock block you can go to 0.06 overbore before needing to magnaflux the block. (413ci). For example, 80cc heads on a 400 make around 8.9CR, where on the 413 they'll make 9.1CR. Not a huge bump but one nonetheless.

now a chevy rebuild kit u can get for like 400 bucks CAN and thats like flat tops, huge cam felpro ect...this by the way is a small block rates, ide have to check on big blocks

Of topic here, but BB Chev parts are more expensive then their SB counterparts, almost the same as Pontiacs for some parts.

im in bc canada and the emissions laws are pretty tight i dont know any states to compare them to but anyhelp is apreciated

Here in Alberta they are fairly lenient, I believe no emissions if your car is older then 78. If your car is tuned properly with a well balanced combination you should have a fairly
Clean running car anyway.

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Now for the heads, I have compiled a list of the common used big valve heads and their flow values. These are un-ported unless stated.

http://www.ultrahost.ca/tj/flow.gif

http://www.wallaceracing.com/ultimatehead.htm is a great link for head information on Pontiacs. I would suggest reading that. Use his main page: http://www.wallaceracing.com and use his head code search to look up information based on year/code etc.

Cam Choice:
The Camshaft, now this is where it gets fun ;) When choosing a cam remember Pontiac's respond best to a dual pattern cam. I'm building a pretty mild 400 for my 68 Bird and chose an Indian Adventures Cam. You'll want to choose a Cam that peaks between 5000-5800RPM I would think. Pontiac warrior's has a bunch of computer generated combo's. (They all use a dual intake, 750 carb, and headers I think plus the cam change). For a streetable cam you dont' want over .470 lift.

http://www.pontiacwarriors.com

They make for a nice research resource. You can also get yourself a copy of Desktop Dyno and start planning.
068 Cam is always a nice choice, or a 041 RAIV (Edlebrock I think makes a copy now). Choose the cam that best fits the rest of your drive train. The 041 will work if you have a standard, though it doesn't produce as much low-end torque as some of the OE cams.

More can be read here (Defiantly a good read):
http://www.classicfirebird.com/hand/jhand5.html

If you care about your intake here is an interesting article and I can put you in touch with a man selling a 68 stock intake:

Intake - You have 2 choices:
1967-1973 OE Intake
Edlebrock Performer

http://www.classicfirebird.com/hand/jhand14.html

I hope this helps somewhat with your car.

holy crap that was quite the bit of information thanks