When I said 8PSI I meant 8 psi from a centrifugal. And if you have a Eaton M90 and not a kit, it will be a paperweight in your garage forever. Forget the Heaton. Your car is an upper RPM flower anyway.
Get a Paxton/Vortech/Procharger/not a powerdyne and do it. Yes a posi , set of gears, and BUILT TRANSMISSION will be MINIMUM to make this an enjoyable car with that supercharger.