I would definily get 3,73 or 4.10 gears, then a supercharger, 6-10psi is good and safe, and while your waiting for the motor to expire, start on a rebuild. Doesnt matter if its a pre 92 block if your going to rebuild the bottom. Now you just have to decide what motor combo you want. 306, 331, 347, ...etc. and re-use your charger.