are you talking late mk2 knuckles w/ 9.4s, or knuckles for 10.1s?
ive got a set of 9.4s that i took off my 92 Jetta 8v. there is atleast ONE bad wheel bearing..
i took off the 9.4s and swapped on some 10.1s off a 92 16v Jetta..
CRSMP5 is right.. the 9.4s are all one piece. the 10.1s are not. you also NEED 14" wheels to clear 10.1" brakes, beware..
i believe you CAN use mk3 stuff, but its going to be 10.1", and need the 14" wheels. your not running 13" wheels are you?