Okay guys i know there is a few threads about this, but none seem to be answering my questions.

I have an 86 FC NA and ibeant to do an FD or RX8 seap into it. Whats the easiest way to do this, with the ecu's, engine mounts and gear boxes? What parts do i need to change, or add?

 

for the Rx8 engine, you're on your own, nobody has tried it yet. it will bolt to the transmission, and it does use a turbo clutch so that is easy, everything else is uncharted. the stock Rx8 ecu needs a LOT of stuff to work, so after market ecu would be easier.

for the FD engine, there are mount kits available here and there, best is a thing that bolts to the FD mount spot, and then goes to the FC subframe. the stock FD electronics are a big job to install, although its been done. aftermarket ecu is a good option. all the plumbing needs to be custom, but most of it is not bad, for instance the oil cooler lines, the FD has a different size fitting on the front cover, but otherwise is in the same place. the rear is the same fitting, but its higher up, so it just needs a longer line.