I recently picked up a Jonsered 920 on ebay for using with my recently acquired Alaskan MK III. It runs well but I checked the compression and it is 130lbs so I figure I will put new rings in it. Truthfully, I want to take it apart because I am itching to tweak it some. Can anybody offer me some porting advice for this saw? I have ported heads on Chevy smallblocks but have never put my carbide to a chainsaw cylinder. If you advise me not to do it than I will take your advice as well. Also, I would like to convert the air filter setup so that I can use maybe a setup like a Husky 3120.