so i found some 17 inch hopsters on craigslist for 500 bucks

http://charlotte.craigslist.org/pts/1208990369.html

what do you guys think?

 

Not sure of the backspacing, but 9.5 rear wheels will extend beyond the wheel well, regardless of the tire height. It might be OK even with stiff suspension, until you hit a bump at 50 MPH. I had 10" Centerlines once that extended well beyond the wheel opening.

Remember, your car originally had a 14 x 7 wheel.

CP

 

Many fastbacks run 17x9.5 with the proper backspacing and the wheel does not extend out.

 

Here is a website that will give you the bs. The part number is on the box.
http://www.hotrodsusa.com/store/arhopsterseries550.html
It looks like they may be for a modern mustang so you will likely have to use spacers.