65 Coronet & 275/60/15's on Rear

I wasn't sure if this should be posted in the tires section but it's 62-65 specific. I'm getting ready to buy Magnum 500's for my 65 Coronet 500 'vert. I test fit 275/60/15's on 8" wheels, but I only have 3/4" between the outer sidewall & the outer face of the wheelwell. Because of this, I'm thinking of stepping down to 255/60/15's for more clearance. Is anyone else running 275's on their 65 Coronet without issues? Or should I step back to the 255's for the extra clearance? The wheels are 8" w/4.5" backspacing.

no problem here

My 64 Polara 500 has 275/60/15 on a 15x8 rim with 4.5 inch back space, plenty of clearence.