Zero pressure cooling system

[Smiling lemon]

Cm2350
Demandated
613k miles
W900
New air compressor
EGR cooler exhaust gas pathway welded shut

I have been pushing coolant out for a little while now and put a catch on the overflow valve nipple. I put a pressure gauge in the cooling system to watch pressure(generally did not exceed 8psi) if I was climbing a steep grade and locked the engine fan to ON, the pressure would stay the same regardless of boost pressure. If I let it rise up to 210 the pressure would hit 15 and the valve would open. I have also had higher oil temperatures since chasing this coolant pushing out issue.

Today I decided to go to a zero pressure system and oddly enough my oil temperature dropped by 10 degrees and my coolant temperature seems to rise slower on the grades that before I was turning my engine fan on for. There truck seems to run at coolant temperatures similar to when I bought it pull is still higher. Oil was running about 240 and now around 230.

I was having overheating before but it could have been superficial feeling do to my previous experience being a company driver and having smaller radiators(I have no statistics or measurement)

I was told with a blown head or any of the such you will be stuck in boiling temperatures and your cooling system pressure will follow boost pressure.