I've decided to rebuild the engine in my IROC. It will be the first thing I do on the restoration. I've also decided to go with a 383 instead of the straight 350 rebuild. It doesn't cost that much more as far as machining and the bottom end kit. My question is, How much power would I be looking at with a stock top end? I plan on siamesing the runners and port matching the intake, plenum, and runners. I will also be getting headers.

Eventually I may install a nicer cam. Depending on the over all cost I may go ahead and pick one up anyway.

But for now just the rebuild with a 383 bottom end.

Thanks.

 

to make good power you will need to get an aftermarket intake setup like the holley stealth ram, mini ram, or superram. the stock stuff is choking the 350 to 4800rpm and aftermarket stock style manifold and runners would still be choking the engine a bit. if you are dead set on using the stock stuff dont plan on making power over 4000rpm. im my opinion it wouldnt be worth a 383 build unless you are upgrading the intake system, check my combo out in my sig, i got 475hp, if i used the stock intake i probably would only be at 350 tops.

 

It will be a lot easier to just do the headers and cam while the engine is out because it’s a lot tighter in that engine bay with an engine in it.

The TPI on my car really kills the power when I'm at 5000 RPM I fell like I'm slowing down and not speeding up. This was after my T-5 swap. So if you want the power you should get out of the 383 the current TPI system wont get you there.

 

you may port the factory heads and install a cam instead of going with the 383 kit. you'd be better off power wise + you would have a more usable powerband than if you stuck with tpi on a 383.