Pontiac 400 build Ideas
 

I am getting ready to do a 400 build for my 65 GTO. This is my first Pontiac and do not know what combos work. I am starting with a 75 TA engine with 6x heads. This is not a race car just a good street car. Would like to get around 400 hp. Any help would be really appreciated. Dont mind buying some parts but would like to stay on a decent budget. :?

Ok, you need compression!!!
First off I'd get the heads milled, with OEM pistons them big chambered 6x heads will have your compression pretty low > 7.6 to 1 , W/ .050 milling it would bring the number closer to 8.2 -1
My lawn mower has more than that. :shock:

Assuming your doing a complete rebuild, have the block bored/sqaured, and opt for flat tops pistons over OEM replacement slugs.

A competiton valve job (3 angle)

Comp Cams XE274H or XE262H would be good cam choices

Edlebrock performer rpm/ or performer RPM air gap intake

750 CFM holley Dp or equivelant carb

Headers > W/free flowing muffs & exhaust

373's gear in the rear & 2500 converter

Goodluck, Cp

search for a ram air v motor...lol

Thanks for the info. I had heard that the low compression would be a problem. I will have the heads milled and a good 3 angle done on them. I have been looking at some I beam rods and Trw flat tops from Butlers. The guy that builds my dirt track race engines said he had some good info on porting pontiac heads so we may do a port job on them as well. Again Thanks for the info.

I would like to have the right 389 tri power engine but I dont see that in the cards. :cry:

good luck with that one.

Ironically the guy that owns Wallace Cacl. is a Pontiac nut and has a whole section on pontiac builds and people who run them, might be worth checking them out.

Zip.

http://www.wallaceracing.com/index.html

My two cents and personal experience-

I would not run the 6X heads. I believe they are smog heads they have a 2.11 int. with a 1.66 ex. and larger CC.

Find a set of RAIII or the RA II series - #48, 16, 12 or like heads. They feature 2.11 int. valve and 1.77 ex valve. and 72 cc’s. Don't do anything to the combustion chambers. These heads are still plentiful on the internet/ wrecking yards or just laying around in Pontiac guy’s garage. Port match/ clean up the ports. Go to Wallace Racing website and look at the head codes. All head specifications are listed…..do your homework before you buy/ build.

Run a good flat top forged piston with any of these heads.

Cam- Crower solid #60311 or the hyd #60211 (I personally ran the #60311).

Edelbrock torker or victor jr. intake. Run a 750 -800cfm dp sq bore Holley

Hooker 1 ¾” primary tube w/ 3” collector with 3” full exhaust.

3.73 gear with a “good set of street tires”.

If you have a 4 spd, your 65’ will run/ should run bottom 12’s or crack high 11’s on a good set of street tires……. I know, I ran the combination years ago in my 64 GTO and the car was VERY streetable and ran the numbers.

Heres my 2 cents, find a 455 run the 6x get a good valve job! Port match a Torker intake not a Torker II run an 800 Quadrajet that has been built by someone who stakes there rep on them. run a good solid (roller if the $$ are there) 520-550 lift range, H-beam rods (they are around $300.00 a set) forged flat tops, make sure your crank is true, block squared etc. You should be around the 8:5 comp. range , pump gas. This combo will last and have gobs of torque, good luck getting it too hook up!!!!

check with butler performance www.butlerperfromance.com