Combines 2 speed gear box

If you don't already have a set then I would suggest installing round bar concaves. They will greatly reduce the agrresivness of the threshing compared to universal concaves. Its possible to change to a 2 speed rotor drive but will be very expensive especially buying new. I doubt if you can find a gearbox in a salvage yard but it may be worth a try. I've always noticed that most places will tell you they don't have whatever it is you're looking for when you call on the phone. I've taken the time to drive to a couple and ended up finding exactly what they said on the phone they didn't have. I'd say you best bet for a salvage yard that might have some would be Abaline Machine.

there is a two speed gearbox available for TR's. but it isn't as simple as intalling a gearbox and running, the right hand rotor gearbox has to be changes also. The two speed mounts right to the RH rotor gearbox and then couples to the torwue sensor. I'm not too sure what a new one would be worth, butI am sure that if you found a salvaged one from a TR 97-TR99 that it would work.