It turned out to be a pretty straight forward process. The pivot shaft that the KX pegs use is the same diameter as the one for the KDX pegs. I had to trim off part of the collar on the pegs and rebend the springs to make it work. My pivot shafts are pretty grooved so they need to be replaced, which should take most of the slop out of the peg assembly. I can't wait to give them a try on the trail. I previously had a pair of DRZ400 pegs that were modified to work. They were the same size as the stock pegs but had actual teeth left on them. KanuckKDX if you want the DRZ pegs your welcome to them, drop me a PM if you are.
Stock 2002 KX 250 Peg:

KX peg with the collar cut off:

KX peg mounted on 89 KDX 200:

Comparison between stock DRZ peg (modified for use with KDX) and KX peg:

Another view comparing the DRZ pegs and the KX pegs:
