Can I use cat 1 implements on cat 2 tractor?

Yes, you can use Cat 1 implements on Cat 2 tractor with bushings and sometimes minor adjustments, and this is common practice on farms that have both sizes. Category 2 tractor has larger hitch pins, lower links 1-1/8 inch diameter and top link 1 inch, while Category 1 implement has smaller pins 7/8 inch lower and 3/4 inch top, so you need Cat 1 to Cat 2 bushings that are sleeves that fit over smaller pins to make them fit larger holes in tractor arms, available at tractor supply stores for a few dollars. You also need to adjust top link length and check lower arm spacing, Cat 2 spacing is about 32 inches versus Cat 1 26 inches, so lower arms may need to be narrowed. The main considerations are safety and performance, Cat 2 tractor has much higher horsepower 40 to 100 hp and lift capacity up to 5000 pounds, so a light Cat 1 implement may be overpowered and could be damaged if you operate at full power, and its narrow width may not cover tractor tracks. Also ensure PTO horsepower and implement rating match. Using bushings is safe if pins are secured with linch pins. However, you cannot use Cat 2 implements on Cat 1 tractor because they are too heavy and large, would overload hydraulics and cause instability. For quick hitch, you may need Cat 2 quick hitch with bushings.