Interesting 72bluNblu - I always thought 15x7 police rims were 4.625 backspace.
Does all this mean a 15x7 4.0bs rim with 225/60 tires and aftermarket bbp disc setup won’t fit my ‘69 Barracuda with stock ride height?
I won't go as far as to say they won't fit. I can tell you that on my '74 Duster when I was running 225/60/15's with 15x7's and 4.25" of backspace with the BBP disks I didn't have a 1/4" of clearance to give up. I wasn't at factory ride height either, but I was a lot closer to it then with those wheels than I am now. So I'd say that combo with a 4" backspace definitely wouldn't have fit my car. I would suspect it wouldn't fit yours either, but body style and ride height make a big difference.