interesting, I did not realize Cragar offered it in 4 inch bolt patter, NOT unilug I guess. if a person changed over to 73-6 disc and obvious 4 1/5 BP, what size wheel ( 14 or 15?) and backspace is required on a 71 Duster? not trying to get off the subject .
Just to clear things up, small bolt Cragars were never unilug. Unilug wheels were designed to fit 4 1/2 and at least 4 3/4" bolt circle. One wheel fit Most all American cars.