Combines cutting corn with a flex head

I would think it would trash the sickles because of the fact of the corn stalks being so thick.

we use a jd flexi head in corn which was flat and yes it gave the sickle a hard time..and we only guess what it was really done to the wobble box my suggestion is to use the corn front if u have to tack some more steel on to the deck plates to close them up more by using the corn front u also take in alot less trash

Rule of thumb -- If stalks are small enough the rolls will have trouble grabbing them and pulling them down, it's not likely you'll hurt the wobble box as long as sections and guards are in good shape. It's a little easier with a rigid head, because you can cut higher up on the stalk.