All 87 and later mustang gt motors are roller cam motors and easy to switch to carb. 87 through 92 have forged pistons. The short blocks are plentiful and cheap I have had several of them and there tough to beat for the money. Add a good hyd roller cam and holley or BG carb rebuild short block and add Afermarket heads AFR 165 and C4 (no overdrive) and you have a rocket. Good luck finding your motor. I have never done it but I think someone make an adapter to put a 700r4 GM tranny behind a small block ford.