I have a 1956 Ford 640 with 4 speed transmission. Generally this seems to be regarded as in the 28 to 30 HP range. Less at the PTO? I am looking at a new Victory or Betsco 68" flail mower. They have lighter and heavier duty models with their specs calling for more HP for the heavier duty models. I am inclined to believe my fairly strong running Ford would handle the heavier duty mower just fine in Low gear, passable in second and probably not at all in third? These 2 mowers are cheaper and lighter duty Chinese manufacture. Based on reviews, I think they would be fine for my somewhat limited use. I have looked at some used mowers, but they have been mostly in deplorable condition and seemed overpriced based on condition.