Combines Will a 7720 handle a 12rn corn head in poor corn

Hydraulics may not be able to handle it. You may have to get bigger rams to lift the platform. You will also probably be way too light in the back end. I put a 30 foot John Deere with a Crary Air Finger reel on my 7720 II and could lift it OK, but not enought hydraulic power to lift reel. Was really light in the back.

A John Deere mechanic told me that driving a 10 or 12 row header should be no problem for a 7720. However, it would be very heavy and might be hard on the final drives, especially if the tank is full of wet, heavy corn. I don't know for sure but maybe the lift cylinders and final drives (planetary) from an 8820 would fit a 7720. It may be easier and more economical to trade up to an 8820 or even rent one. Sometimes when I have tried to update something I end up with a worse machine than I started with.