Tree Monkey is as good as they come. His cost is in his sig, $300 includes shipping back to you.
Parts are extra, so is additional work. The added work, if found, will be cheaper than a dealer would charge you.
I’ve been porting saws for a few years now, and I may send a few to him myself. There’s more work involved than one may think.
Porting involves increasing compression in most cases (by creating a popup piston or cutting the squish band), optimizing combustion, optimizing port shape/size/timing, increasing exhaust flow to increase performance and saw durability.
It’s a big balancing act. Everything I stated above has to work together. In some cases, builder use parts from other models to optimize things. Sometimes what works on one model is detrimental to another. Some saws take 10 times the work of others for performance gains.
You are paying for experience, and
@tree monkey has a lot of it. He’s kinda old, but he’s got a few good years left in him.