Need some help on rims and tires. This is what I am looking at:
FRT G60-15 Goodyear polyglas 8.4" tread width
Rear L60-15 Goodyear PolyGlas 9.0" tread width

Rims Rallye 15x 8
These come in 4.50 or 4.625 backspace. Will the L60's fit ok in the front? Which combination is better for the 71 RR's, same size all around or the mix?

Not good with backspacing determination so to clear the L60-15 tires how much backspacing is needed for frt and rear to avoid clearance issues if there are any. I an keeping the stock ride height.