Just want to make sure

My truck is a 1992 4x4 1500 extended cab. It has the 5.6L and an 5-speed manual transmission. From what I've been reading, it's a NV3500 transmission but I wanted some validation to that. The truck/tranny has 179,000 miles on it and is still on the original clutch so my gearhead buddy is going to help me replace it this weekend. I just want to do some reading on the tranny before the weekend and want to make sure I'm reading the right thing.

Also, what is "getrag"?

Thanks,

Fish