Front Wheel to Fender Clearance on my 68 Fastback.

Typical. That's a very tall tire.

225/60/15 on 15x7 4.25" backspace barely fit. And sometimes rub. There are people here that run 225/60/15 without problem and others that have caught the fender when backing out of a driveway.

Common to see people run 215/60/14 with 14x6 ralley/mopar rims on 67-69.

It varies per the alignment and past collision damage.

More positive caster adjusted at the upper control arms will pull the tire back for more clearance a little.