Check the builder threads. MHR, Matt is doing some really cool things with these 85-86 motors. He's got a billet reed cage setup, and you could possibly ask him if he's got the add on powervalve setup finished. I believe he also has a really good 85-86 pipe design also. Depending on what you want done, expect anywhere from a few hundred to a couple grand. Only thing with Matt is that he's a one man show with salvage services engine buildding and a bike shop, so it could take a month or more, but his work is very much worth the wait.

I'm not sure exactly. He was telling me about it last year sometime.