A friend of mine had 15x8 corvette rallyes on all four corners his 69 and they rubbed in the front during turns. I think he had 255/60/15s on it. He ended up swapping them out for some 15x7s and a lot narrower tire. They did look good though.

 

Backspacing is wrong for a 69. Had them on mine, and they rub the outer lip on the rear fender. The front worked OK with a 225/70 if it's not lowered.

 

GM 15x8s used on Vettes have 4" backspace, which really is not enough up front on a 69. It's not really enough in the back either, but they work better there than up front on a 69.

 

I ran 235/60 rear and 225/60 front on my 8in ralleys and it fit well. The owner before me ran 255's in back and it rubbed the inner well, the marks are still there.

 

67 vett had a 15x7 witha back space that uses a deep ring that looks like a 8 inch wheel in the front. Ran them for year on 67 and 68's with no problems and a 225 60 15 tire.

Not sure what the back space is though?

 

I run 225/50/15 up front and 265/50/15's in rear on my 15X8" corvette ralley's. I do have issues of rubbing in back on outer lip, but I corrected with airshocks. No issues up front.

I plan on switching tire sizes to match what ever BFG Radial TA I can get. I would like to swap someone two of my ralley's for 4.5 or more back space for the rear.

 

I've bought mine at http://www.carid.com/custom-wheels.html and don't have troubles with them. Swap is not a bad thing at all, but as for wheels, I prefer to buy new - just my thoughts.