It should hold up just fine at 5 mph.   


But, 5 mph is pushing the top end on speed if you want the stalks chopped up good with chopping rolls.      There is a noticeable difference between 4 mph and 5 mph.    6 mph will look pretty ragged.  


What’s the price on that head?   The aftermarket stuff would be well over $20k new by itself.  

We have the Calmer and Yetter stuff on a 1290 Jd head on a 8010 CIH and  love the whole combination.