[Hydro]

That 38 psi is not gonna cut it -- the pressure reading with the ICP sensor disconnected is a made up number by the PCM programming, so ignore that one

7.3 guys don't seem to be much on air testing, but I would do that test to see if the system can hold pressure
you have "spare" oil ports on the head (driver side pretty easy to get) -- jump a battery to the IPR to make it close off and see if the air stops

Fire up ForScan and lets see if any codes are popping up -- your cts3 is a fine monitor, but can miss codes

 

[Hydro]

Could remove the little plug on the driver side head to help bleed the high pressure oil -- there is on that is fairly easy to get to -- or remove the ICP sensor and crank over until oil comes out, will get the driver side head at least