Just passing along a good experience that I had doing business with The Gear Shop located in Middle River MD. I had to replace my NV3550 due to a severe internal knock. These guys remanufacture most makes of manual transmissions and transfer cases. Most used 3550's online are going for a minimum of $600.00 and there is no guarantee that it is any good to begin with. These guys charged $895.00 for a remanufactured unit with a full 12 month warranty. The owner even called me before I drove down to confirm that I actually had an issue in my trans and not somewhere else in the drivetrain as he stated that he would hate to see me spend my money if I really did not need a new trans.
Check these guys out if you ever need a replacement transmission or gear case. They also have an EBAY store/page.
The Gear Shop
1107 Middle River RD
Middle River MD
410-477-4327 ask for Will