The rest of GM's trucks can be ordered with option G80.. It's a Eaton mechanical locker..
http://www.traction.eaton.com/prod2.htm
I can't help but wondering why it's not an option on the H3 or even the H2.. Not sure if it'll fit in the H3 as an afterthought or not... It's not an air locker or E-Locker, but it's gotta be better than nothing and it's a WHOLE LOT cheaper for the parts if it will fit in the H3 diff without further mods..
I've heard they work pretty good, but are about as delicate as the front diffs in the H3..
Bebe you got the answer..??? Will the G80 fit the H3..??
Rob