Wheels for a duster offset and backspace
Personally I don't like big oversized wheels on a 70's automobile, but I find 15'' to be fine since that is what I run on my 76 Dart Sport, 15x7 in front and 15x8 on back. I like the classic look better on these cars but then again I am probably much older than you. By the way the Demon, Dart Sport and Duster are essentially all the same vehicle, the Duster was first, then the Demon and then the D. S. replaced the Demon name due to religious beliefs.