Thanks Neil, All stickers are long gone from the Camaro unfortunately
Reviewing my tyre / wheel strategy as the rears have 275 60 15 but the rims don't have enough backspace (only 3.5") so there is very little bump room due to the tyre sticking out slightly past the arch.
Using this handy calculator:
http://tire-size-conversion.com/tire-size-comparison/
Looks like 255 60 15 is a nice fit -should give an inch of extra room and also pull the sidewall in (will use a different wheel too, the current one is 10.5" wide, shame the backspace is so small). It'll only be a fraction taller than stock then, so no major worries about catching the arch on the tyre.
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