Did Chevy make a C-series 4x4?

[joeydurango]

Just picked up a SWB 4x4. It's titled as a 1972 C10, but I believe it's a '71 because of the rearview mirror location (ceiling) and door panels (vinyl, not molded plastic). This truck hasn't been lifted and I know it's been 4x4 for at least 25 years (so if someone converted it, it was a long time ago). The truck came with a box of trim that came off it during its recent paint job, and there are well-worn Cheyenne 10 badges.

My question is: Did Chevy make a C10 4x4, or were there K-series Cheyennes? Everything I'm finding indicates that C-series = 2wd, K-series = 4x4, but I thought the Cheyenne package was only a C-series thing. Am I mistaken somewhere, or could this be a really old conversion?

Photo attached just for kicks.