Does anyone know anything about the Blackhawk Max-Flow Stihl High Performance cylinder and piston kit? There's one listed on Ebay for an 066 and the description says that it will add 30-40% performance. My 066 is getting a bit tired and I've been considering changing rings, but if anyone has any experience with these, maybe it's the way to go. Does anyone know who builds them and if their OK? 30-40% sounds too goo to be true and you know what they say about that....