Help with IDing rear diff

[hatzie]

Originally Posted by Dleslie212

Part of the reason I bought this truck was to be able to wrench on it, and learn things, and I just think it’s cool to know every inch of it like the back of my hand. I think I’m going to wait and rebuild it completely myself in a few months. I’ll orobably completely redo everything except for the axles themselves

It's a K series so you'll need to match the front and rear axle ratios.

It should've been stamped a little closer to the carrier mounting surface but it's still reasonably readable.

Looks like the part number is 3817778
The gear stamp looks like 11:41

GM 3817778 is a 3.73:1 gear set.