Rear end s10 help!!

I have a 95 s10 4.3 vortec 4x4 manual transmission the stickers in glove box is destroyed I don't know what rear end I have but I want to replace it I think it's the gu4 what all rear ends can I use in it being 4x4 with out tearing stuff up can I use a 2x4 rear end im new at the rear end Business I just know it dirty! :naughty: