You are answering your own questions.. 2% leakdown is what you mean't but explain the air you heard, where was it? Did you pull the dipstick and also the oil cap? No pun man but a p28 is meant for a single cam not a high compression dual cam!! P28 would run lean and cause cylinder temps to sky-rocket, this alone could cause damage to a ring-land.. Not saying that is your problem, I'd look more at venting the block since the valve cover will only help a little.. And get that hooptie tuned!!

As for the other guys talk, we all list info for others to help, yes I agree with age and wisdom but some know more than others and it can be a 12yr old for that matter...lol, keep it cool guys..

Later!!