Dd15 epa10 oil pressure low after inframe concern

Hello all.
Looking some experianced advice from wrenker:
I just finish my motor inhouse inframe dd15, new liner, new piston, new connecting rod, new main rod bearing ofcourse, new oil pump and oil suction module, new oil pressure sensor, new injector, new camshaft, cam gear, etc...
Late last9 I designed to do first fire after priming oil from 0 to full of level at oil module, priming fuel at low pressure fuel pump.
Everything look good and sound smoothly at the 5th cranking, however i noticed my oil pressure at the first start is at 66 psi instead of 75psi. I expect it gonna be 75psi on oil pressure at cold start. After 2 time short idle on low and hight, I designed to shut em off and dig into the job to see if anything happend but i cound not found anything yet to this point.
Does anybody have any experienced about this issue? I hope nothing to do with the crankshaft but upper cam housing causing this due bearing worn out. I am going to replace those cam housing/ rockers for today and fire again in the afternoon.
Any input i really appreciated...

 

Idk why the website keep delete my post.
Btw, rocker shaft was in correct position. Install mechanical gauge still showing low pressure.
I wonder if i missing something during inframe? After new cam housing and all the shaft inside the cam housing plus rockers on exhause and intake side (because excessive oil escape during low idle) still doing the same low pressure on cold start @68 psi by dddl/mechanically gauge/and event new sensor.
Now i am facing with new issue: blowby from atlest 1 cylinder after 30min hight idle . I am notsure if main bearing damaged due i used 80W90 gear oil to install those main/rod/pistonring bearing as detroit require? I know most of tech out there using white grease 105 but since it is my 1st inframe i try to stick with detroit documen, any input on this part?
The fews thing i reuse is the head/crankshaft/block/injectors/turbo.
Very Bad start up.
I really appreciated for all of ya input

 

This engine i have coolant in the oil, crankshaft locked on cylinder 5, i checked the crankshaft journal found fews line at num5 and few more line on different main bearing but not very heavy deep to me so i think it was ok for reuse this crankshaft.
After inframe i used my hydraulic oil pump to prime the 12 gallons of oil throught oil module, i was thinking maybe too much pressure during the priming from the hydraulic pump that may damaged something on oil system internally what do you think?
Also i found fews thread mention engine seized by air compressor, what is the symptom on this seized and how to know if air compressor causing brolem?
I am going to drop the oil module to swap from different truck to narrow down every possibility thing beside the crankshaft today .