The 15x8 wheel with it's low offset can fit the front but it's really tight. Looks like it sticks out too much but people make it work. Good picture in this thread
http://forums.pelicanparts.com/porsche-autocross-track-racing/840193-what-size-tires-you-using-15s.html#post8375762
Here's another thread with discussion on the fronts.
http://forums.pelicanparts.com/porsche-911-technical-forum/822066-15x8-fuch-wheels-up-front.html
The search function is your friend. Just have to be patient/diligent and try different terms. But that's easy to say. I was doing some searching a month or so ago about this same question for my own car (i'm considering 15 in. wheels for the '86 for track use) and I saw a thread with a bright green car that had closeup pics of the front, showing very clearly how tight the fitment is at the fenders. So tight that you'd think to yourself "c'mon dude, there's no way that tire doesn't rub!"
I can't find that thread now......
