Rim Clearance

Thanks! I was told that Ford went with little bigger fenders after 91 and that I would have issues runnin 17x9 in the front on my 90.

very true. my '89 rubs a bit on full lock on the fender extensions with a 245/45 on 17x9's. rack limiters may help that problem, personally i just dont turn so far.

shouldnt have any problems in the rear unless you go bigger than a 275. up till then the only thing that may/may not be a problem is the quad shock, you may have to flip or remove it.
 
If it has drums you are all set.

What do you have on front?? If it's just the Mark 7 rotors, you may not even be able to run the FR500 up front. The center cap wont fit and you may have clearance issues with the snout of the rotor
 
Properly??? SN95 front brakes and spindles

The spacers may push 17x9's too far out. You'll have to test fit them really. It also depends on what brand wheel you purchase