Paul - rad, man. Did you follow the porting guide on the Wiki? This is something I've always wanted to do. Raise the exhaust, port the piston, and raise the intake. Then shave the head. If you did all that then I believe it'll do almost 50.
Dude - get a better pipe! You'll definitely have 50 all day with a Ninja or Doppler. Ah....but then again, it wouldn't be a 'poor man's' Moby.
I'm in the expensive super Moby club. There have been two significant straightaways where I've been around 60. Once at the Stinko-de-Mayo rally where only Tommy (who went 70! GPS confirmed!) and Elliot were in front. And they both have 60+ easy.
I'd love to come out to Haverill and see what you've done and talk Moby forks. I dropped some Honda forks on...but might upgrade. We'll see. You've probably seen it a million times because I post it so much, but this is my super Moby. Love it. Waaaay better than my 80 Metra puch rigid. Way better.
<a href="http://s95.photobucket.com/albums/l142/bqeberle/?action=view¤t=IMG_6489.jpg" target="_blank"><img src="http://i95.photobucket.com/albums/l142/bqeberle/IMG_6489.jpg" border="0" alt="Photobucket"></a>