i know this is kinda stupid but

[swervin ervin]

I never knew these numbers existed until I started buying original GM Parts and Illustration catalogs. These things are great for helping to find part numbers and identifing parts for our trucks.

Anyway, I looked for the numbers on my van and couldn't find any. I checked the 85 and did find those. They are small, about 1/8" in size and like Dave said, they were stamped by hand. They used a die set to do it with so they are not deep at all. You have to look real close and have some bright light. Mine were about 6" out from the carrier, on the passenger side, almost dead center on the front of the tube.

The code on my 85 was BX3. This translates to:
2.73 ratio, 11.15 x 2.75 brakes, Exc. G80.

Happy searching.

Oh, if anyone finds their code and wants to know what it means, I'll be glad to look. Although I haven't looked at them in great detail, I have catalogs for all years of our trucks, even vans.

Mike