Blueaggie,
Yes, a 4 3/4" bolt pattern rim was used on the 1965 GS. The larger Buick models would have a 5" bolt pattern. Rather than buy old steel rims to be used with hubcaps, have you considered buying new rims instead? New rims will have no rust and will be easier to balance. I bought a set from a local Goodyear store. If you are buying an older set of wheels (with no tires mounted), roll them across a smooth floor first to help detect any damage to the rim edge.
John Egel
