Linux2501

I am having a problem with my rb20, for one I have a new plug its causing these problems.

I compression tested the entire motor and its showing 90 across the whole board, no big difference at all, and when there is oil in the cylinder its 110 on all of them. I think my motor would run like crap if it only had 90 psi but then again its too damn cold to tell if the exhaust coming out the back is white of if its just moisture in the gas tank from the car sitting for 5 years, it has 93 octane and some heet so like i said not sure if its crappy gas or if its a blown head gasket. please shine some light on this for me.