Welcome Jon, nice truck. thumbs_up The sheet metal looks to be in good shape. I don't have the answer to your question, but I'm sure someone will come along and enlighten us both.

FYI: I believe your truck may be a 3/4 ton based on the extra side support on the bed. Mongo is a GMC expert, I bet he knows for sure.

John

~ J Lucas
1941 Chevy 1/2-Ton
1942 Chevy 1.5-Ton SWB
In the Gallery
1959 Chevy Apache 32 Fleetside
My Flicker Photos!