66 Dart wheel size

Hey guys-
I'm looking to put Ansen mags on my Dart. I can only find 15x7's for 5x4" bolt pattern. Will this work on my car, or do I need to find 14" rims? What size tire can I get away with on 15" rims for my car?

Thanks!

This pic has inspired me to find Ansen's... :notworth: