17x8 Mustang Wheels on 64 Valiant Questions

I was wondering if the stock a-body 8.25 is wider then the stock 7.25 when mounting wheels on them? Also when converting to sbp drums in front to bbp disc's, does the track width become wider in the front also? The reason I ask is because I have a set of 1994-95 mustang cobra wheels that are 17x8 (back spacing is 5.72) with 245/45r17s all around and It looks like I will be needing spacers all around to use them if I convert to bbp.