I don't think those compression numbers mean much. I've seen engines fly well with 20/80 compression's! You might have been having valves sticking or something else going on.
I put new millenniums on this year also. My reason was I was getting 2 hours to the quart...lots of ring blowby. Oil on the belly. After install, I flew 10 hours at redline and 1000' pressure altitude to break it in. Open up your airflow and redline the engine! Try to minimize taxi time. I now have about 30 hours and in the last 5 I can't detect any oil consumption and no oil leaking now (suspect reduced crankcase pressure).
I'm still fighting with a MA3SPA that is running way to rich at idle. Fowling my plugs on landing approach and taxi even tho I got it leaned out like crazy. In flight the carb works fine. I use auto gas and that fowls plugs way worse than 100LL. But still, I want to get working so if there are any carb experts out there, help!
Mike N3QP Q200