I’ve run that combo in my 68 barracuda (same fender dimensions).
the 225/60/15 in 15x7 with 4.25 backspacing was very close. I think it would rub backing up in certain situations. When it’s that close alignment, parts, past body work, all can give you tolerance stack. On one end, it rubs. In the other end it doesn’t.
there was someone years ago here that tried that BBP, 4.25 backspace, 225/60/15 combo and it rubbed his 68 barracuda. He changed to 215/60/15 tires.
I ran offset UCA bushing that moved the upper ball joint back. And I ran 1/2 degree negative camber that brings top of tire in. I also ran poly strut bushing that are less compliant than rubber. That keeps the wheel from pushing toward fender when backing... a bunch of tiny things. Some might have done nothing. But I am stacking stuff in my favor.
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these are 225/60/15 in front
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