2wd XJ's and MJ's made after February of 1992 will have the 4wd style outer knuckles.
The spindle type knuckles use pre 1990 style brakes.
But, won't post 1990 style knuckles bolt up to a pre 1990 Dana 30 inner C?
Going to have to buy calipers and rotors anyways just replace both sides.
It is nice driving with the 2wd front end, lighter steering and smaller turning radius.