I'm rebuilding my s5 motor and my front housing is thrashed. I have one from an 86 but was wondering if I could use that? Mazdatrix website says its different and if so, what are the differences? Thanks.

 

are you talking about the front rotor housing? or the front cover? the housings should be the same. You can even use FD housings. The front cover wont work because the oil "o" ring was made larger in the later engines. I mean, it might work, im not sure, but I wouldnt try it.