Stay away from the used 350 and 450 Deeres with shuttle shift trannys. If they very many hours on them, the discs are probably already glazed, and you don't want to the the sucker who came along at the right time, trust me. This problem was recently discussed here. Don't let it happen to you. The CAT D3 of yore has a rock-solid torque convertor. That's where I stick my money if I wanted powershift.