The 16V and 8V use a different type of cable. And while I have never tried it, I would bet that you could use either cable on either vehicle/engine as long as you use the proper clutch cable bracket that mounts on the side of the engine. They both use the same tranny (5 speed, that is) and tcases (no matter what tranny it is behind...manual, 3 speed auto, 4 speed auto).
The intakes and heads are different. They share the same blocks, clutches, flywheels, water pumps, alternators, ps pumps, ac compressors.
So there are several things that interchange, but there is a lot of stuff that doesn't either. So if you want to know if something specifically interchanges, let us know what you are wondering about and we can probably tell you.