max Duster tire size

I'm looking at a 1970 Duster for my 14 year old son, since he wants a Duster like his dad and since I have an extra 10 pt cage and a set of 15x3.5 Centerlines for the front already. But I'm wondering if N50x15's on 15x10's will fit without sticking out. Has anyone got these to fit, and if so what did you have to do. And what offset worked. I'll relocate the springs 3", but will I have to mini tub it too?