When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Most are 5 lug on a 4-3/4" diameter. But some of the larger cars had a bigger pattern. I remember always looking for "Intermediate GM" wheels at the Junkyards when I was a kid. Should be the same pattern for Firebird (not a Chevy BTW), Camaro, and Vette. I KNOW some Impalas had a bigger pattern in the 70s and my 95 Caddy is different too.
Do a search online for bolt patterns. I'm sure some wheel company must have this online.
"I could be wrong but I think most GM cars are 5 on 5 bolt pattern."
Actually most GM cars are 5 lug with 4 3/4" bolt circle. It is true that some full size Chevy's had 5 on 5 in the 70's/80's as did some full size Pontiacs, Buicks, Caddy, and Olds, but everything 5 lug from the intermediates down were 5 on 4 3/4's and a majority of the full size over the years were 5 4 3/4 also.