On mine TCI clip I used a 4in back spacing and a 225/45/17 tire with no Issues what so ever. But with yours heidts front end you might 4.25 BS. Also do a search on 17x7 wheels and you'll find plenty of info on 17 for our first gen cars.
I have the mustang II front as well, with the extra narrow frame. I just bought some MB Old Schools (look like Torque thrusts) in 17x8 with 7 mm positive offset. They were also about half the cost of the AR's! They fit great all the way around. For tires I got 255x40x17's. I could have actually used some 8.5 with the right offset, but couldn't find anything like that that wasn't cost prohibitive.
If you are going to run a stock width Nova 5 lug rearend you better stay around a 4.5 or 4.75 backspace in the front because the rear requires that much backspace and if you run less in the front the front wheels will be deeper. I have had to correct this problem a few times at my shop when the wrong backspace was ordered.