I ended up taking .05 off the cylinder base ,( old farmertech with the [KS] casting symbol) and using a meteor piston with caber rngs and a base gasket delete.
A friend of mine came over with his Blue thunder 660 which we both agree is a very strong saw and he mills with it. He had an opportunity to run my build and it blew him away in the difference, my throttle response is better and the rpms climb higher ,but I think noodling a log with the full 34" bar and full comp really had him grinning.
I know it's stronger than my 394xp ( for now).