70 stage one heads one 75 455 block/trying to build a 400+hp 455

[kyle14x7]

Hi I just picked up a set of 1970 stage one heads, with stainless steal valves for my 1975(not a stage one) 455. I am wondering if this set up will work, or if it has been done before? My block is bored .40 over, and i have aftermarket comp. cam, lifters and a 600cfm edelbrock carb, a pretty basic rebuild. As far as the rest of the engine everything is original, from the intake to exhaust mainifolds. I'm trying to make 400hp or so out of my engine, without doing any more machining. Any suggestions/comments or concerns? Thank you, Kyle

[pmuller9]

I know you will get plenty of feedback on this one so here's my 2 cents worth.

I prefer other cam companies for the BBB. Comp Cams uses the same profile for the intake and exhaust. The Stage One Buick head has a restrictive exhaust port and requires more duration or lift or both for the exhaust valve for better power. Most of the other cam companies use a split duration profile for the BBB.

The larger Q-Jet is a better choice for a carb and others may suggest something other than the 600cfm Edelbrock.

Which Comp Cam do you have?

Paul

[kyle14x7]

Its part number 96-203-4 SN# VL0093-10
But you are correct, the intake and exhaust valve lift are exactly the same .469
The intake opens 28 BTDC close 60 ABDC
The exhaust opens 68 BTDC close 20 ATDT
The duration @ .050 Intake 218 Exhaust 218 Both have lobe lift of .3026

[pmuller9]

Its part number 96-203-4 SN# VL0093-10
But you are correct, the intake and exhaust valve lift are exactly the same .469
The intake opens 28 BTDC close 60 ABDC
The exhaust opens 68 BTDC close 20 ATDT
The duration @ .050 Intake 218 Exhaust 218 Both have lobe lift of .3026

Kyle

The preferred cam is the TA 212 which has the same 218* intake duration @ .050" lobe lift but it has 230 * exhaust duration

The following link shows a build similar to what you are doing.

http://www.carcraft.com/techarticles...ons/index.html

In this build they use a 750 cc holley

The Comp cam would work well with the Stage 2 head which has the better flowing exhaust port.


Paul

[kyle14x7]

Awesome, I'll look into getting the carb and cam asap, any recomendation on the lifters? And any thoughts on the 70 stage one heads? Thank you for all the help so far, Paul

[pmuller9]

Kyle

If you are getting the TA Performance TA 212 cam, get the TA 1405 lifters.
When you order the cam ask them what lifter they recommend just to verify my suggestion.

I am not the carburetor guru here but I do know from everyone else's experience that for the street the original Q-Jet spread bore works best.

Do you have the original quadrajet carburetor that came with the engine?

Do the heads have a new set of valves with a valve job or will the heads need work?

Paul

[kyle14x7]

I dont have the original carb, it came with the one I have on it when I got it. As far as the heads go I was told they only need light clean up, so hopefully all is well with them.

[pmuller9]

Is the 1975 shortblock assembled ?

If so what pistons where used?

Paul

[jonlisa97]

If interested, I have a Big Block Buick Maxi 3 cam with Rhoades lifters for sale. Willing to let them go cheap since I got them extra with a car I bought. PM if interested or check my for sale thread out. Thanks

[carmantx]

The stock 75 455 engine had an 800cfm carb. Your new build will want at least that and maybe more to run it's best.