Here is the actual belltech kit on their website
BEL 824I'm not sure what that kit on the summit site actually is as I got a little excited seeing the steering knuckles included. I have a 98 2500 2wd that I want to drop and the only kit is the belltech with a shorter spring , I've seen a few pictures of these installed but some of the reviews I've heard is the shorter spring makes a harsher ride with it bottoming hard on the shorter bumpstop?
Does your 3500 have control arms or is it a solid axle , I think the solid axle 3500 is for the cab n chassis ?
As far as the difference between the 98/99 and 2000-02 the steering knuckle changed from spindle mount opposed tapered bearings in a heavy rotor like our old mopars are to a hub/bearing assembly with a replaceable rotor ... I think the rotor is the same 2wd and 4wd when the change happened ..., the upper control arm also has a different style upper ball joint., I don't know if the later style ball joint is compatible with the early control arm and vise versa, I do have the later upper control arm I haven't tossed yet and I might try putting it on , it attaches the same to my 98 when I replace the upper control arms in the spring . It's too late for the 2nd gen now but I wish someone made a drop spindle style steering knuckle like they did for the 1500.