Older style orange corn head would be for the F and G only,and the black heads need a different mount and drive for whatever model they will be installed on.
landM heads won't fit. There are some FG heads out there. The orange F heads and the A series black heads will fit. I have a FG430 that was on a F and now is on a F2 that I will be selling soon.
Check with Homier in Payne, OH. Also get a copy of the Farmers Exchange there have been some wide heads listed in there. A good orange FG 440 will cost about $250 or less, an A438 will be hard to find. A436 heads are easier to find. I'm also in NEIN near Fort Wayne.