The Norwood cars will have the "Z28" or "28" on the trim tag. On the 72 and later, the VIN will tell you which engine and that will also determine a Z28. Go to MadMike's site
Second Gen Camaro info to learn all the details on the 2nd gen Z28's. Ond of the weak spots on those cars is the rear frame rails tend to rust out completely. The rockers also rust pretty good.