Popping throught the intake...please help!!!!

I was reading on another forum site that some guy had a similar problem and removed the heads and found a blown head gasket between 1 and 2. Could this possible cause the pop and if so, shouldn't I see some smoke (or water vapor) out the tailpipes? Could the kirban be going bad? When I adjust the Kirban, the gauge will move so does that mean it is ok? Also, I heard the kirban can be adjusted w/o taking the vac line off. Can someone confirm this? Thanks!
 
I set it with the vac on. So should I take the vac off and put it to 50? Also, can my Mass Air be too big? It is the big chrome Pro-M one..I have heads and cobra upper and lower though...