Wheel Vintiques "Mopar Rallyes" (67 Barracuda)

I was going to say I doubted that there would be a rim clearance issue based on a mere 1/4" additional width on the inside edge, but then I went out and looked under my car, a 67 FB with factory discs and 14 x 5.5 Mopar rally wheels. The clearance between the rim and the upper control arm was just under 1/2" (my small tape measure blade which is 1/2" wide wouldn't quite pass through the gap, although it might have been getting hung up on a wheel weight). So if everything else is equal, your new rims would leave slightly less than 1/4" clearance. Since this is fixed gap (unless your wheel bearing are failing), that may be OK, but I agree it seems tight. It didn't look like the ball joint itself would come into play. Although, possibly an oversized tire with a lot of sidewall bulge might cause a problem.

Suggestion: measure the real backspace of your current wheels, compare that to the real measured backspace of the new wheels, and place a lump of putty or playdoh slightly thicker than that on the inner rim of the old wheel, remount it and see if it hangs up, and then remove the wheel and measure to the contact mark.