03 cobras on a 92 gt....

Just did the exact swap to a 90 GT. We put 285-40-R17 Goodyear Eagle GSC on the rear, 17X9 wheel...no quads...no rubbing. I would say 315's will fit, but I would highly recommend extended lugs and wheel spacers if need be. I know a Mustang tuner here in Mt. Clemens Michigan that has 345-18's on the rear of his notch...which is FRIGGIN sick!!!!

For the front....we used the same 17X9 wheel, with a 275-40R17 Goodyear Eagle Gatorback. They were Corvette tires and they fit with some help.
1. 1 1/4" wheel spacer on each side because they rubbed the strut...HOWEVER he has coil over suspension and a tubular K member and control arm. The wheel hit the spanner adjustment, and the tire rubber the spring.

2. They do rub and not even at full lock..I told him this would happen, but he didn't care. He just wanted the stance. I think extended lugs up front with 2 1/4
" spacers would be better, but I would not recommend it.

3. He has drive 5 miles and already has rubbed the paint off of his rocker molding edges. I just repainted the car too.... damn

Im surprised you got them back there with no probs. My 03 cobras with 275s ripped a hole in the quad shock Now that they're removed im seriously considering some spacers to get them back on there because the car wheel-hops like a mother****er. I would not suggest the 315s simply because without quads they will probably just hop and you'll never be able to use up the extra tire width.

i suppose if you replaced your control arms w/ quality aftermarket units, you could eliminate the quad shocks w/o any problem. Otherwise, most people reportedly have issues w/ wheel hop if they're running the stock suspension and no quad shocks.

I've read on more than one occasion where guys get wheel-hop from removing their quads, even WITH aftermarket upper/lower control arms.

Seriously ... is it really worth it just to be able to say you crammed some 315's under there? If you're that hard up for traction, buy some DR's and/or lift bars, and forget about 17"+ wheels - bigger tires with shorter sidewalls don't grip any better than a wide set of 16's.