Hey DG_300EX, I've got the same mods as you do, except the wider rear axle and I've got 22" Holeshots on the rear and I drilled my airbox cover for a great breathing improvement. I'm curious of your performance compared to other quads you might ride with. I've only ridden with a Polaris TrailBlazer and well, there was no comparison even without my new tires and airbox mods. This year the TrailBlazer has been replaced by a 2000 Scrambler 400. I've read of the respect I should give to this quad, but on the trails we ride in the woods I wonder how we'll match up. We're heading out next Tuesday for our first ride of the new year together so I'll find out first hand then. How will my 300EX stack up against stock models of 250R, 400EX or Banshee given the woods riding I said I do?

Hillside Hawk

 

2000 300EX---All Red OEM plastic, TC Racing piston, cam, valve springs, and CDI black box. WhiteBrothers E-series exhaust and header pipe, power filter, and 14 tooth front sprocket. CT Racing head porting and carb boring. 8--1 inch holes in airbox lid. HoleShot XC's on Douglas Red Label rims.
Renthal bars and Custom AXIS suspension is on the way.
Too answer the question about the black box mods. Tom Carlson will mod you current box for $90. This changes your ignition timing and raises your rev limiter by 1000 rpm. So the machine rev's faster and longer. Or you can buy a new black box for $190. That's what I did.(so I can plug my old black box in if my girlfriend plans on riding the machine)
Overall I am impressed with the outcome of the quad. It is unbeatable in the woods and on a tight track. But still lacks top speed in the open. You can't have the best of all worlds....

Chris 00' red rocket