I will still be way short of busting the tranny too.

The main reason why my car only has a four speeds when porsche had been making five speeds for years is because of the big sturdy gears and case used in the 930 tranny and the limited space in which it had to fit. There was no way to make it strong enough for its race car predecessor and have enough gears for 5 speeds.

Short of some different turbos and intercooling its the same tranny and engine that powered many a 600-700HP 935 race car.