I have a pretty mint 2004 Team Green KX500 that I will post some pictures of shortly. I just went though the bike to grease/tighten/locktite everything and here is what I've noticed is unique about these Team Green bikes so far: The frame has welded on guards for water pump protection, the exhaust bracket problem is fixed with reinforcement, the radiators are fully welded (even the air bleed was welded over) with spacers to flare the radiator shrouds out more (to collect more air I'm guessing), a stainless steel plate has been riveted to the subframe to ensure the chain won't eat through it.
These Team Green bikes are pretty awesome, and I will try to post a bunch of pictures so to show some of the mods the factory team was doing. They had these bikes dialed in, and they were extremely reliable. Mine has a Varner motorsports engine, but I have not opened it up to check out the mods. The engine was done by Varner and the supsension by Acme, then the bike was not ridden for several years, so no reason to tear the motor apart yet.