I was wondering if there is a difference in crank case pressure,when useing different oils,I was checking out my car getting ready for the new season when I noticed my intake gaskets were pushing out from the intake almost to the point of causing a vacuum leak. The car still runs strong 9.50 at 144 mph , but kind of baffeled at what could cause this. The only change I made was going to the 20/50 green oil mid season I was using valvoline racing 20/50 and never had this problem.Ive been using the shogun evac system and has always worked great , also been fighting valve cover leaks which also makes me think theres A problem. Anybody have any ideas?