This Allis Chalmers B-12 had been a parts donor tractor when I bought it. The cylinder head and some other parts had been used to keep a Simplicity model 2010 running. Along with the missing parts the gears in the bevel gear box had been stripped out. I got the engine running first and then swapped out the bevel gear box with one I had. This tractor has the optional hydraulic lift unit on it.