car overheats

[Wizard]

Actually air is pushed into the coolany passages, not sucked. 140psi compared to 13psi.....

And it's actually quite common for a DSM to blow a headgasket like that. Considering your compression numbers, I would doubt that the head needs to come off, shaved a touch and new gasket.

Another way to verify this:
With a good radiator cap, fill the rad neck full when cold. Fill the overflow to low mark. Drive the car for a couple days. Then when it's cold again, if the overflow is full, but rad. neck low or empty.....HG.

Wiz