did you have the motor at operating temp also when holding wfo for compression reading??? if a crank seal is bad it will be the clutch side if its rich. that means its sucling transmission oil into combustion chamber. if it were running lean constantly it could be a flywheel crank seal, cuz it would suck air on that side. have you noticed trans level dropping?? i would still also run that fucker. i usually after a rebuild will fire it up, let her idle for a few to get hot, blip her for a few mins then shut off to cool. do that again, then after 2nd cool down start putting engine load on it,going from easy load to hard load the more heat cycles. try that, esp if you havent put load on it yet.