Wont a 6 pot be a little tight in the bay? Not to mention heavy. (117kgs)
Especially with it being quite wide due to the heave cant.
Oh and a problem with the diff could come about with the single 'ear' like load bearing mount. Will this throw off how the loads are transmitted through the chassis?
If you find ways around all the problems i would love to know as rusty E30's are sooo cheap now. And the mechanicals are easy to work with as well as being reliable.
Chris