I would say if you go slow 1 power head would work ok. Not sure how much you plan on milling but if it were me I would shorten bar up to like 36 or 42 so many less drivers to pull and a lot easier to sharpen. This winter used a 7900 to mill a 36inch sugar maple with a 42. It was slow and we were spraying the chain as we went but it got it done.