If you go with the Aftercooler model, you can make more power.
This sort of build pretty well maxes out the stock bottom end of the motor. You are probably over-building unless you rebuild the motor with forged pistons and rods.
With a stout bottom end, and street cams, you would be around 350hp+ at the rear wheels (above 430hp at the flywheel).
Of course then you're going to need to rework the
tranny, and get a proper stall converter and J valve kit.
Suspension comes next, starting with rear lca's.