Do I have enough clearance for tires?

That's a good idea! I will check the other side tomorrow. You're absolutely right though, I've never owned an old car that has been the same on both sides.

I agree a 4.5" backspacing would be better, but I already had these wheels and I'd like to save a little money if I could and not buy new wheels. If I ended up getting new wheels, I would probably just run a 15x7 on all 4 corners, and just put a little wider tire in the back. New wheels are about $110 a piece.