Box Blade Sizing for Kubota L3901

[old and tired]

Not going to recommend anything to you... Just letting you know what I use. My L2800 HST and a 72" box blade works very well for me. I've flatten the sides of hill to make a flat spot that campers stay on and dug a new road down to the creek with mine. Moving material from the high side, down to the low side... to make a flat road. We have mostly dirt with a few rocks thrown in for fun

 

[Sid Post]

The Kubota L-series tractors are lightweight for engine size. My recommendation is to buy the smallest box blade or land plane you can so you don't overwhelm the tractor.

I run loaded tires in my L-4600 and I find it doesn't have enough weight to pull as much as the engine supports. I will spin the tires before I bog the engine. YMMV

 

[MF243RedTop]

6'. Cover the width of the tires plus an inch or two extra on each side. I dunno the width of a 3901 (what tires?) but if a 66" box blade covered it well, that would give you more ripping and pulling power.

Exactly the right advice .. strap more weight to the box if it's not digging to your expectations...and or add more weight/loaf rear tires if it won't pull it .

 

[BadgerCheese]

I'm running a Land Pride BB3584 which is 84" wide. It's a touch wider than my wheel base, and it pulls a LOT of material. The weight is 853lbs, so there's no nudging it into place to hitch it up, but it makes an awesome counter weight to the FEL. At 45 hp it's at the upper end, size wise, for my tractor. But when you set it down to dig in, it digs. I've only had to put the tractor in FWD or use the differential lock a couple of times pulling a full box up hill.

For the saying so, the rear tires are filled.

 

[mo1]

Ag tires on front and rear, 4 wheel drive and diff lock available as well.
I should also mention that it's an HST.
Wheel base according to tractor data is 63.3 inches, but I haven't measured mine.

I would say a 5' box blade would be a better choice than a 6' box blade. That would still be wider than your tractor as you noted the width is 55". I had a little Massey-Ferguson tractor in the past that was very close in physical size and dry weight to your Kubota, and it was also an MFWD unit on ag tires. It also had a loader on it which added a more weight too. The ag tires were not fluid filled. The 6' box blade I used with it was really too much for that tractor, it would lose traction and spin the wheels if the box blade got somewhere between 1/3 and 1/2 full of gravel on a dead flat driveway. Adding fluid to the tires would have helped some, but I somehow doubt that it would have made enough difference in traction to let it get the box good and full. I'd suspect that another 1/2 to 3/4 ton or so would probably be needed to get enough traction to pull it well.