[vujade]

I believe the front will work out perfect with no spacers needed, all under the stock fenders.

I am using 17 x 7 et55 with 205/40/17's on the front with stock brakes & I had to use a 10mm spacer. I have done some calculations & it seems like the 944T brake rotors will eliminate the need to the 10mm spacer.

In the rear, I believe you are going to have to run wider fenders.

Those 8.5 x 17" wheels w/ et50 are going to widen your track about 35mm per side on their own. The early alloy trailing arms will widen the rear approximately 25mm per side. And the 944 brakes will also widen the rear about 25mm per side. So this is a total of 85mm wider (about 3 1/3").

I know that under the stock fender you can be as much as 25mm (1") wider per side and still be under them, so if you are 85mm (3 1/3") wider per side, you will need a fender that is at least 60mm (2 1/3") wider to cover them, maybe a little more.