Same Size Tires
 

I know there's a lot of discussion on tire size, but not much on what same size tires to go with all the way around. I have a 1967 GTO that I am restoring and it came with a new set of still in the box 15" x 7, 4" B.S. Rallye ll wheels. I was comparing the diameter and tread of the stock F70 x 14 (26.20" diameter, 6.70" tread width, 8.3" section width) and optional F7.75 x 14 (27.02" diameter, 4.50" tread width, 7.65" section width) tires to 15" tires. I was thinking of going with either 23560R15 (26.65" diameter, 8.5" tread width, 9.25" section width) or 21570R15 (26.90" diameter, 6.40 tread width, 8.70" section width). I am looking for some feedback and recommendations. Thanks

without a doubt
235/60's if you want all 4 the same

Agree with this. It's the widest size tire you can fit on the front.

Personally, I agree with the 235 60R15.

But it also depends on what you prefer. The 215 70R15 will look skinnier and taller, more akin to original. If that's the look you're after, go that way.

Performance difference will be a consideration too. The taller, skinnier tire will act different (squirmier) than the shorter, wider tire.

To my eye, I always want the tire shorter and fatter when possible, simply because I like the look. Performance enhancements are just that, enhancements.

Hope that helps. :)