Certainly do able but I don't think its a good idea.   

Those IH heads with knife rolls take real power if you're trying to move at any real speed in good corn.       I'm thinking to make it work good you'd have to have ~35 gpm @2200 psi, just for the head.  That would be around 40 hp.

Unless you have a whole lot of unused hyd capacity to use I think you're going to remove one headache and replace it with a bigger one.