My stroker took a while before the blowbye stopped. And yes the detonation could have kept the rings from seating, however the most common cause is a rich condition whereas the cylinder walls get coated with gas and it washes the oil off. Not only will this cause the rings not to seat it could possibly put a lot of stress on the rings causing premature failure. Drive it for a few days now that you've got the detonation solved and run another compression check, it should be a little better. Look for a weak cylinder, which might indicate a problem. My engine finally settled out with 200 +/- 10 lbs.