You might try seeing if you can get a Pat’s quick hitch or something similar for the lift arms. Whether you can do that or not would depend on the actual dimensions of the lift arms. That would give you the CAT 1 pin diameter and keep you from having to spread the arms past the pins for implements with the bolt on pins. You’d still need them wide enough to hook to the pins but wouldn’t have to spread them past the pins. Pat’s is a bolt on system so you don’t need welding or fabrication skills to install. You might find that causes you to need a longer top link but unless you’re running a hydraulic top link, top links aren’t very expensive.
I was kind of surprised that the lift arms on my 47hp Kubota don’t spread as wide as the arms on the much smaller 9N and they’re just barely wide enough to fit around the older implements we have with the bolted on pins. As best I can gather, the arm spread is limited on the tractors with R4 tires to keep them from having any chance of ever swinging out far enough to hit the wider (as compared to R1) R4’s. I’ve sort of considered turning the pins to the inside on some of the implements but it hasn’t been absolutely necessary (just have to be careful the tractor is well centered on the implement at hookup) and with the brush hog I’d be a bit concerned about binding from interference when lifted all the way due to the hitch configuration on the implement so I haven’t turned them around.
