74 Duster wheel and rim sizes.

I would send them rims back, they are the same size that was on my duster when I bought them, the back space is like 3.5", you have to run a super skinny tire to get them to clear the fenders. like a 185 front and a 215 rear.

You need a 15 x 7 with 4.25" of back space to put any size tire on a duster.
I have stock 15 x 7's all the way around with 275/60/15 and 215/65/15 there is no rubbing issues.