I have a 65 belvedere conv. w' 14' original wheels and tires. I want to put on A/R Torque Thrust 17X7 wheels. Does anyone know if these will fit without rubbing, and what size of wheels should I use?
Thanks for any help and suggestions.

I don't know the '64 specifically but in general, 17's fit older MOPARs fine. Backspace will matter for fit in the fender wells but it shouldn't be too sensitive. Don't go crazy on tire size.

As a guess, which I hope others will confirm/correct, I'd go for around 4" or a bit less backspace on 7" wheels. 225 or 235 width tires should be a safe fit. One consideration is wheel width and low profile tires. With lower profile tires, wheel width needs to be matched closer. 8" width and around 4.5" backspace may work better with the tire sizes you will likley use.

If you have a buddy or a tire shop that will loan you a wheel/tire its easy to verify fit. That's what I did on mine.

17 inch rims fit fine as long as you buy the correct ones. I covered this topic in my B-body book. I even used a few cars from Moparts members as examples of how to do it right.
http://www.moparts.org/moparts/books/index.html