Wasn't there a fuel octane requirement decal located somewhere on Z28's....or no??
My Z has 2 original decals on the core support. One is the usual emissions decal, there is enough legible on it to determine that. The other decal closer to the radiator cap is not legible anymore but I can tell something was there.
I'm guessing it was either a coolant decal or fuel octane.
Any help appreciated.