ok edit, you guys and your stock pistons, composite hgs, and high boost

Not to get too far off subject but there's things other than hihg boost that will screw up a composite hg like coolant with hose water, high engine temps, oil that's contaminated with gas, etc. I'd just think that someone who's dropping serious lute on a performance car would want the comfort of having a high quality hg and head studs. To each their own.

Interesting points you bring up, if you would like to disscuss this further feel free to start a new thread. I would be more than happy to say a few words on the subject. Now back on topic.

Problem solved. The air leak was coming from my throttle body. This problem started right after install of my JMF Smim. I also put on a 1g throttle body I just bought. Chris suggested re-routing my coolant lines so they don't go into The throttle body. I drove the car and no more air bubbles as well as no more overflow into the overflow tank

if you re-route the coolant lines, bypassing the TB, make sure you do the FIAV disable in my tech article http://www.dsmtuners.com/forums/article ... sable.html
otherwise the car will idle high. Even if it doesnt, its a good thing to disable to keep the idle more consistant. If your BISS screw is outside of 1.5~2 turns out from soft bottom range, your IAC wont be able to compensate for changes like AC, headlights, fans, and other load bearing things or sudden idle fluctuations.