x2 on all helpful posts already made.
I believe you can run the 98-99 knuckles on your 00+ without issue. If memory serves me correctly, the live axle trucks don't require any seals between the bearing and the knuckle...and the knuckle and CV. Only the PVH (98-99) trucks did. If the little tube gets in the way, cut that sucker off. Best bet to make darn well those knuckles are usable for you is to take an afternoon and tear apart one side of your truck and see how the knuckle and CV fit to the SL knuckles. I wish I could help you better, I just don't remember. But do remember I've never used a seal on the knuckle and my SL has been on mine since Spring '08.
It only goes in one way....I too installed one of the cross members the wrong way and had to flip it. And I also believe the crossmembers have pre-drilled holes on the bottom side. And remember, torsion bars are different length's....one side is shorter than the other. And you can get away without the $175 torsion key tool by releiving all pressure from the key and removing anything holding up the lower control arm from drooping all the way. Everything that needs removed to accomplish that, needs removed to install the lift. Install is reverse and kind of cumbersome if only one person.
'01 XLT disguised as a '03 Fx4 Level II
Big. Loud. Slow. Bright.