My MX 5100 is cat I at the tractor side.
My implements are all over the place. My woods DS96 mower has Cat II lowers, but a Cat I upper pin hole. My rear blade was all Cat II, but I had converted to cat I when I had the L3400. My bushhog 306 was cat II lowers that I put cat I pins in, also a cat I toplink.
When building my toplink cylinder, I was gonna do a cat I eye for tractor side and cat II for implement end. But in the end I opted to go with both ends having cat II, even though I could have gotten by with a cat I on the tractor end. I appreciate the extra strength and meat and more weld surface of the cat II eye vs a cat I, even though I will still be using a 3/4" pin. A 3/4" x 1" bushing for that eye is no big deal, once on the tractor side, it will rarely be removed. And I'd rather tack weld the bushing in if you didnt want to fumble with it as opposed to going with a smaller eye. Thus basically like having a cat I eye with the meat/strength of a cat II eye.
