I'm repairng a freinds cars that was over heating. There it was shy 1 gallon of water. I replaced the thermo and filled it up with distilled water. After heating up, there is white foam and coolant being presured out of the upper radiator hose and ton of white foam on the radiator cap and hole.

I ran a compression test before leak down and after. Here are the results:

Before 90W was added:
180 180 170 180

After 90W was added:
210 190 190 190

I'm suspecting a head gasket, but I'm unsure what to think about the leak down results. The oil looks just fine. The white foam doesn't feel that oily. Any suggestions? And no, I did not add Mr. Bubbles to the coolant.