Looking to buy a pair of ET Streets for my '69 RS/SS for an anticipated big block transplant. I'm planning on using 15x8 Rallys with 4.75" BS. I looked around MT's website and found a 27x10.50-15 that I thought might fit. They say it's got 8.9" tread width but 10.6" sidewall width--are these going to fit without rubbing? Any other recommendations on tire size?