Head Gasket test questions

[Blacked Out Outlaw]

A little background on the truck, it's a 07 F250 with almost 78k miles with either the looney tune, or Innovative's Xtreme race in it since 2k miles. This past summer I had 2 puking/coolant loss episodes but everything else has behaved normally and there haven't been any other problems so I just left it alone. I decided today to connect a pressure gauge to the degas bottle to see what would it would read. I want to report my findings to see if this is normal as I know what is supposed to happen if there is a problem but I'm not sure how it's supposed to act if everything is okay. The gauge stayed at zero for about five minutes of idling. Then didn't rise during a minute or two of easy driving. Only after I started beating on it did the pressure slowly rise. After ten minutes of going full throttle both from a stop and while rolling the pressure barely reached 14 psi. After my last run I drove around for another 5 minutes and the pressure dropped to around 11-12psi where it stayed until the end of my drive and another 5 minutes of idling. I used a decent quality pressure gauge so the readings should be pretty accurate. Does this sound accurate for a truck with head gaskets that are not blown? Please let me know your thoughts.

[Term3]

I would say no to head gasket failure as when we did the same test on a buddies truck the pressure spiked up to the 16 psi relief pressure within thirty seconds of a WOT high boost run. Just some added info his truck was not blowing white smoke that we could tell even though his head gasket was obviously blown. Just verify the cap is not relieving pressure at lower then normal pressure.