Mike - mine is a '71 pan so IRS long axle with stock drums on rear. Have pinky clearance on the tight drivers side. I have 185/65x15 Bridgestone Pole Position tires mounted. I did sand the wheel opening lip and some off the inner fender.
I like the EMPI/CIP1 5 bolt 911 look alloys with 5" backspacing - would just need new drilled rotors and drums.