I reccomend Hetrick Racing for porting. His two Blaster riders went first and second on the holeshot at the Red-Bud National this Weekend. The top dog for Blasters used to be Baldwin motorsports but I believe Rich Hetrick is the new king. The # is (814)676-0477 tell him Garrett sent you.

Garrett Lowman; CT240 Blaster, YZ490

 

Check out www.eric-gorr.com. I don't know of anyone who has had work done before by him, but I was very impressed with his technical expertise. He is doing one of my FL350 cylinders right now. He uses computer software to model the port changes for the specific engine, where you want the power and what kind of gas you want to run. If someone's knowledge is based on past experience, you will only be guaranteed a good job if you have exactly the same thing done.