While doing some detailing the other day I noticed some cracks starting to appear near the rims on a couple of tires. Tires are about 10 years old an probably overdue for replacement. I've got 245/60/15 BF Goodrich Radial TA's on my '75. This would have been about the equivalent diameter of the old F70-15 that the '68 to '72's ran. In '73 GM switched to a G70-15 and kept that through '77. In '78 they went metric with a 225/70/15 with the 255/60/15 being optional. I'm thinking of running the 255/60/15 TA's next spring and wondering if anyone has tried that size on a '77 or older Vette. I don't have any clearance issues with the 245's but would like the slightly larger width and diameter of the 255's. Any thoughts?