Where would I find the rim size on a '97 30th Anniversary Z28?

I need new rubber, but Goodyear doesn't make the stock tires anymore - so I need my rim size to figure out what tires I can buy.

 

Stock rim on a Z28 is 16x8. The stock tire with the "performance tire" option was a Goodyear GS-C 245/50ZR16. Tire Rack has them in stock, although I wouldn't stick to a tire design that is seriously outdated as the GS-C.