Well if I'm not mistaken:
Smaller flywheel: All 12 & 24v 5-speeds
Larger Flywheel: All 6-speeds 1999-2005 NV5600
Not sure if there are variations on the 5-speed clutch used between the 12v and 24v engines and especially the 5-speed 3rd Gen trucks. Same deal on the 6-speeds between 2001 and the 3rd Gens
Vaughn