I am slobbering at the opportunity to get my ride out next week. It's getting a "ground-up" rebuild to a 383 with all the important goodies, JE pistons, callies, manlys, etc. The only thing still original in the engine are the block and the valve covers. It also has ported LT4 heads/intake and a set of headers.

My question is: Does going to a 383 affect the compression ratio, or do much more than add some low rpm torque. Since the max SC impeller is rated at 6K, I sense that most of the power will be in the mid-range.

It will have a mild cam and an ATI 8# SC.

I am assuming about 400 RWHP.

 

I am a little confused. if you are planning on using a P600b, I would advise you to step up the blower.

also, its gonna take a LOT more pulley to make 8psi on that motor, then a stocker.. and at 8psi it will make 500+rw. with the right cam, it will probably shift around 6200(even with a mild cam), so you will want to pulley the blower to hit max rpm around there.. you can(and should) over spin it a little. yes, if everything else is the same the compression ratio will be higher. but of course, you want it lower so run bigger dish pistons.