5 speed manuals from 8V and 16V 1.6L engines are the same externally, and will interchange between the two. The only difference internally is the ones that came behind the 16V engines have a .795 5th gear ratio, as compared to the ones from behind the 8Vs, which have a .86 5th gear ratio.
3 speed autos are the same between the 8Vs and 16V 1.6 engines.
4 speed autos are the same between the 8Vs and 16V 1.6 enginess.
I was thinking the trannys behind the 1.8s were different and won't bolt up to a 1.6.....but I can't remember for sure.
