I started with a 97 kx500 owned it from new had to pull the engine to replace crank seals and was just going to go over it. then i found a 2000 kx250 frame on e:bay got i for a buck + shipping so I'm going to use as many parts off the 500 that i can i bought sub frame,air box,triple clamps 250,rear brake master cylinder,01 shock,reed cage,kx250 pipe, tank & seat off e:bay I'm trying to keep it a low cost build about $500 for these parts.
I had to bush the frame for the 500 swingarm bolt then for the 500 radiators move top radiator mounts and fab up the bottom center ones and just got the frame back today from the powder coating guy I'll send comment and photos as it go's together