72 Duster Tire/Rim Size?

Ok newbie here lol :glasses7: :newb: I have a 72 duster and we just dropped a new front end conversion kit in it changing the bolt pattern from a 4 to a 4 1/2. Since we added the disc brakes it's changed everything up! I'm looking at putting Cragars on and was told a 15x7 rim would fit it. Anyone know for sure? Now once we get that figured out, if it is a 15X7, what tire size do most of you run on your fronts? Any help would be greatly appreciated!! Yes I'm a girl and not all that mechanically inclined so if I say "do-hicky" or "thing-a-ma-bob" I apologize up front. :D:D:D:angel9: