The raers are definately ok, the front might end up rubbing the frame under lock to lock.

When I got my '82 (in May '00), it had the original (although dry-rotted) 255/60R15 Eagle GTs, and it didn't rub at all. For safety's sake, I got BGF TA/Radials of the same metric sizing, but they DO rub at lock. I think (I didn't measure) the TAs are a bit taller & skinnier than the GTs; I didn't drive it much with the GTs, but I 'think' they handled a bit better, too. The TAs ride nice, and I'm told they wear longer, too. I detailed Corvettes at a local dealership from '73 to '82; I think the front wheel-wells are 'shaped' different on the '80-up from '79-earlier models by the factory (is this why '79-earlier rocker mouldings don't fit '80-up?), to help clear the 255s.....

from the Corvette Black Book.....
"Starting in 1978, the 255/60R15 was made available as an option, which required fender trimming at the assemblt plant for clearance."
1978 numbers...
"18,296 cars were equipted with 255/60's
26,203 cars were equipted with 225/70's"

I put 4 255/60R15 Cooper Cobra's on last week and she looks and runs fantastic. My 80 L82 doesn't rub at all and she corners like a dream. God I love this car!