what year RX7 are parts compatable with 1990. Looking at a couple for parts (engine, drive train and body). Is 1987-1991 compatable in every way or limited. Also can an automatic be easily converted to manual transmission?

 

There are far too many parts to list. Many things can be interchanged, but many can't be. It's mostly the electronic components that differ.

Engine electronics are all different between series, which means swapping engines is not a simple task. The options are changing much of the wiring or converting the engine with an S5 front cover, manifolds & electronics.

Automatic to manual transmission conversions require custom a transmission crossmember, manual pedals, manual driveshaft, transmission, starter, clutch master/slave cylinders & a shifter surround.