[clinebarger]

A cracked head &/or a blown head gasket will put combustion gases in the coolant, Displace the coolant....Then the engine will get hot. I didn't read any of this as a symptom in your posts??

Coolant fouled plugs are a symptom of the engine sucking coolant on the intake side.....Vortecs are Notorious for doing this, I saw one a few weeks ago that filled #2 cyl. full of coolant & hydrolocked with NO external leaks at 50,000 miles....It was just intake gaskets.

If your head is cracked it would be in the intake port, That is Highly unlikely.

Compression test are just about worthless...Unless something major is wrong.
Ive seen engines with a low of 120psi & a high of 160psi on different cylinders run fine. What was your readings anyway??

A leak-down test is the only true way to know a cylinders ability to seal.

Get the head Magna-Fluxed, Lap the valves yourself, & Put it back together.