Bought a junk Dixon 4516 mower from ebay for $500.00 had a blown 16hp kohler, found a good used 20 hp kohler twin on Craigs list, installed with some refitting only to find both hydros leaked pretty bad, this mower was sitting for a number of years seals dried out. Was lucky enough to find two new hydro gear transmissions on ebay for $400,00. total. got them installed and she is good to go when the snow is gone. I already have another Dixon 4516 which I work the holy hell out of, they are tough little mowers. Bought both of them cheap, and look forward to getting a lot of work out of them this spring and summer. Any one who knows how to use hand tools can do this, however an engine hoist is pretty much necessary for this kind of work. I am 76 years old and had no problems, for you young guys it should be a piece of cake. Cheap is good, works for me.