help with pontiac 455 engine?

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hi my names josh and i just bought a 79 firebird t/a clone with a 71 or 72 400 block with 455 rotating internals so a 455 engine. i really need help. im tearing the engine down and rebuilding it. i want to get as much HP and torque out of it that i can. can you tell me what parts and brands i should buy to get this engine to peak performance while still being street legal. i kinda want to put a supercharger on it but i also dont. so i dont know weather i am or not. also what kind of hood scoop should i put on it i was thinking a true shaker or tri slot blower


other things it has:
411 posi rear
turbo 400 trany
bnm shifter
it has headers just dont know what kind i want to get new ones
holly intake
600cfm carb i want a better carb
2 1/2 inch flowmasters with cat in it

Id really apprecite some help. i work on cars and grew up around muscle cars just dont know alot about pontiacs
 
So it's a 400 Pontiac with a 455 crank, rods, and pistons? I could be wrong, but I don't think that would make it displace 455ci. Cause if you put a 400 Chevy crank in a 350 Chevy, it displaces 383ci. So it might be around 430ci or so.

You want to get as much horsepower and torque as you can? Remember, when you start beefing up the engine you have to beef up the other components too. Actually, 1971 and '72 400's have pretty good heads in them (especially the '71s). The engine is probably making lots of torque if it's a 400 with a 455 crank, because the stroke is so long. A 600cfm carb will actually flow enough for most street performance applications, but it's probably kinda small for a 400+ci engine. Maybe upgrade it to a Holley 650 double pumper or a 725 Road Demon. You don't want to overcarburate an engine, which is a really common mistake. Also install a hotter cam but nothing too wild with the factory heads.
 
Basically the only thing to do is change to different carb like 740cfm or double pumper. maybe a cam. It is not a 455 it is like a 380. The 455 I had with my old 74 formula was 230 Hp and 305 torque with posi, 650 cfm, cam and automatic with Hurst ratchet and shift kit. also shorty headers with them coming out before back wheels to give more torque, basically if they built a 455 now it would have about 600Hp and torque but back then you got a boat anchor as posi was aftermarket and tranny sucks. Its 0-60 was 5.4 but in 1/4 it was 15.9
 
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