I'm asking for a few opinions. I presently have all the mods in sig on a stock 350 making 405hp at the wheels. I am wanting 450+. I have seen a lot of threads about the 355 buildups being awesome. However, I am thinking that since I already have worked heads and a big cam that a 383 might be good for me. I want to go all forged internals so I can spray or add a blower at a later date. Really, for now, I want to get 450+ at the wheels on a naturally aspirated setup. Later on, I'd like to add mild boost and shoot for 600hp or so at the wheels reliably. Is this a realistic goal? The heads flowed 280cfm @ 0.600 lift.

 

with a fully ported intake (including raised runners) I think its possible. Also may require bigger cam than GM 847 .. I know lots of people will not agree with me.

 

the key for the 450+ rwhp will be keeping it a 6 speed 10 bolt car, also lightening up the valvetrain and drivetrain. Anything to lessen the parastic loss.

 

Def will req. a bigger cam, and more porting on the heads to get closer to 300cfm or more to support that hp.. the limiting factor will be the heads and intake...