7.5 must be a typo. I have 15x8 with 4.25 BS and 275x60x15 Nitto's on my 68 Barracuda and that is about the max on BS I can handle. Stock A-body 8 3/4 with ss springs in the stock location.
I thought the same thing until I went to the RC Comp website. They’re 15x10” wheels with a 7.5” backspace.
So there’s a ton of reasons they won’t fit. Wrong backspace, the rims are too wide for stock spring locations, the tire is too narrow for that rim. And we don’t know if the car is 5x4” or upgraded to 5x4.5”, so the bolt pattern may be wrong for those rims too.
