Ah, I see you have a more specific goal than I realized.

I just thought you were looking for a 2500 LBS car with about 350 HP and torque that handles great.

Now I know you just want to build a ford go-cart for the SCCA.

I still think it would be a lot cheaper and easier to achieve something at nationals with a hot BS car than a with an old ford in SM.

To answer your boost question I think you would certainly need to be in the 20-25 PSI range.

Force Fed may have a more exact number.