Stamped Numbers In Sheet Metal

[mrein3]

I've been doing some painting on my truck.

First let me start by saying my truck is a mutt. 1971 chassis (long wheel base 4x4). 1972 Blazer th350 and NP205 transfer case. 1972 Chevelle 307 temporary power plant. "New" to me box made up of pieces I bought in Wisconsin 10 years ago plus a re-pop LHS bedside I picked up from daburb. 1968 Golden anniversary interior.

NOTHING matches.

My normal operating mode with old sheet metal is to remove all the old finish, treat it with a mild acid wash, epoxy primer, then color.

On the back of my cab, and on the tailgate are stamped numbers. "39" on the back of the cab and "47" on the tailgate. The font appears to match so I would guess this was some factory marking.

Has anybody else noticed this? If you have a non-mutt, do the numbers match?

[ryans69chevy]

I've seen numbers like that as well on various panels like my dash panel and cowl. I found them after drilling all the spot welds and removing those pieces. I've come up with the conclusion that it was something to do with the assembly of the truck. Instead of GM calling a part by its name or what we would call it, they gave it a number. The factory workers would then know exactly how to and in what order to assemble everything since a parts name could be misconstrued. You and I might call a part something totally different, so numbers might have been a way to solve that problem.

This is only my assumption, it may not be true.

I guess as I'm typing this, I'm wondering if in the factory assembly manual they have the same parts with the same numbers?

[1968 K20]

I know this is an old thread but I also would like to know. I noticed prepping for paint on my truck that I have 37 stamped in the bottom back of cab like you picture but also on the center of the firewall above the intake and also on the passenger side door on three different pieces of sheetmetal that was used to build the door and window frame. I have not found any stamps in the driver side door but all that I have found are 37.

[BigBird05]

Just a guess, but periodically QC will pull a part, cab or whole vehicle and measure it. That might be a QC control #.

[Lee H]

36 stamped on end gate. Cab is stamped but can't remember number. 343 etched on fire wall, corresponds to job sequence number on the build sheet. 37 stamped on passenger door. Fremont truck.

[1968 K20]

Thanks for the replies. My truck is a 1968 GMC K25 built at Fremont. Maybe it is a stamping per the plant the sheetmetal is assembled.

[mrein3]

Originally Posted by 1968 K20

I know this is an old thread but I also would like to know. I noticed prepping for paint on my truck that I have 37 stamped in the bottom back of cab like you picture but also on the center of the firewall above the intake and also on the passenger side door on three different pieces of sheetmetal that was used to build the door and window frame. I have not found any stamps in the driver side door but all that I have found are 37.

Are you calling me old?

I never did get a good answer about those numbers. Maybe it corresponds to a part number in the assembly manual? I just don't know.