Iv'e been thinking of trying to upgrade cluching on my 80 invader. I'm wondering if it's same taypered crank as cats,polaris ? I have a cat 9 tower to play with,BUT i'm not sure what waits, or spring to run.I'd like to bump engagement to 4500 to 5000 rpms.I don't plan on doing anything with secondary yet.Any help or advice? Or am I stuck with stock kaw cluch? Thanx