Bought this tractor yesterday and it's a significant size upgrade from my previous tractor. St some point in time I will buy a larger Bush hog. How large a cutter would this tractor operate?
Kubota L3830GST, B7500HST, BX2660. Formerly: Case 480F LL, David Brown 880UE
The general rule of thumb is 5 horsepower per foot, by that you could run a 10 ft bush hog.
Realistically speaking, if you are not running in heavy grass, you could probably run anywhere from a 10-foot to a 15-foot, you will just need to go slower with the 15-foot.
I might lean towards a 12-foot batwing just because it would be easier to move on a trailer if you need to move it someplace (no overwidth permit needed).
If you're thinking about 3 pt. hitch type, remember you have to be able to pick it up. I think Kubota publishes data on how heavy an implement can be for each machine. Check your operators manual.
For my L47 the max recommend is a 6ft cutter weighing 926lbs.
There's a big jump in price when you go from a 72" to a 84". Unless you are doing large areas the extra foot may not be worth while. If you go to a mid or HD cutter the weight can go up too. I have a 6ft Bushhog 286, which I'd call a medium duty and it weighs 962lbs. The 7ft cutter in the same series (287) weighs 1247lbs, which would be a little heavy for your machine, IMO.
Kubota L3830GST, B7500HST, BX2660. Formerly: Case 480F LL, David Brown 880UE
Note that if you're going to a 7-foot, you'll probably be just as well off going with an 8 foot as an 8 foot is usually twin spindle bush hog so it doesn't stick out as far in the back and can be easier on the tractor to lift and get into tight spaces.