My '69 EB has had 7.00 - 15 tires on it probably forever. I put 2 new ones on it a couple of years ago & had no problem getting them. I now need a couple more & my supplier says that bias ply 7.00 - 15s aren't available in mud grips. Only 10 ply trailer tires. They said I didn't want the 10 ply tires as they'd beat me to death anyway. If I go with similar sized radials, I'll have to change all 4, when I don't really need but 2 right now. Anyway, out of curiosity, I checked the tires that I have now. They are 8 ply tires. I can't imagine 2 more plies changing the ride that much. I also have found some 7.00 - 15 mud grips that are 10 ply, so the tires are out there. Anyone have experience in going from 8 ply to 10 ply tires & is the ride really that much rougher? My EB rides pretty well on the current 8 plies. Thanks for the input.