I have NOT found a CAT 1 implement that doesn't fit my BX2350.
Simply put, all BX's are not "limited" CAT-1's.
I had some left-over CAT 1 attachments for my Ford1210 that all fit my BX2350. It was something I researched before buying.
6 foot Rear blade=fit
5 foot Rake= fit
4 foot Bush Hog=fit
4 foot rear finish mower=fit
I did not need to turn any pins inside-out, either.
I just got the KK II TG-48 (not the XB) and it fits just fine.
So, they did not need produce the XB series for the current crop of BX's.
The XB is CAT 1 pins, with CAT 0 geometry. I spoke with KK folks before purchasing. They produced the XB to meet the demand of the lower HP subcuts, they told me it was more about power needed to drive the unit, than simple geometry, although they did take that into account as well.
Perhaps the original BX models were "limited", but the BX2350 is a CAT 1. I would venture to say the BX24 is also, unless they engineered them entirely different, but I don't think that is the case at all.
I would suggest when we give info about a BX model , that a specific model be cited.
To my knowledge:
BX1500 = Cat 1 "limited"
BX1800 = Cat 1 "limited"
BX1850 = SAE CAT 1
BX2350 = SAE CAT 1
BX24 = SAE CAT 1
I cannot speak for the other BX models, not for sure.
The Category rating also relates to HP ratings, as well as the pins, and geometry.
Category 0
For Tractors with up to 20 Horsepower
Top Link Pins are 5/8 inch in Diameter
Lift Arm Pins are 5/8 inch in Diameter
Category 1
For Tractors with 20 to 45 Horsepower
Top Link Pins are 3/4 inch in Diameter
Lift Arm Pins are 7/8 inch in Diameter
Category 2
For Tractors with 55-65 to 90-95 Horsepower
Top Link Pins are 1 inch in Diameter
Lift Arm Pins are 1 and 1/8 inch in Diameter
Category 3
For Tractors with 95 to 100 Horsepower and Up
Top Link Pins are 1 and 1/4 inch in Diameter
Lift Arm Pins are 1 and 7/16 inch in Diameter