can you bolt tranfercase to a 2 wheel drive trany and use in 4x4?

As long as you find the right extension housung for the trans, yes. Can't say if you need a different main/tail shaft assembly, though.

This anwer is almost two years late but it may help others thinking about transmission swaps, The transfer case may be a secondary problem to converting your engine from a flex plate to flywheel & clutch setup. You will almost certainly have problems with the RENIX ECU. Your 87 automatic isn't computer controlled but the engine settings may be set for an auto tranny and may not take well to a stick shift. My suggestion is to: #1, follow the advice above about seeing if the swap is mechanically possible. #2, swap out the entire engine, transmission and ECU from the donor vehicle and eliminate the problems with adaptation.. By the way, if the 87 longbed is still available and isn't completely trashed I'd like to know about it.