advice on rim/tire sizes

[Wraith]

Sounds like you have several problems going on. If you haven't went through the rear suspension yet stickier tires are going to play hell with worn out 100K/30 year old rear bushings.

275/60 on a 7" is going to roll over and bulge more on the sidewall, 7.5" is the narrow side recommended, I have ran them on a 7" but they fit better on an 8" as they will square up better on the rim.

 

[Huen79H/O]

Theres someone i seen on here that had 15x7 front 235/15 and 15x8 295 50 rear , looked very good !

That was me it is on my hurst olds which is the gbom and the 295 rub when I have four people in the car and hit a bump or when. The body rolls need to roll the fenders also I installed wagon springs and rubber spacers