yeah... but it takes a few seconds to get from 0 as in not running, up to that 90.... so that's why I thought (maybe wrongly) that I might at least get a blip immediately upon startup before it gets to that level....
being as how I just got this thing and just got it running for the 1st time since bringing it home, and changed the oil before I ever heard it run for that 1st time, I'm thinking that I should put some seafoam in or maybe dump like 1/2 of the oil and top off with kerosene and warm up, then change again to free up the pressure relief... but unless the high manual gauge reading is as you suggest, the reason that my gauge isn't reading, I'm trying to address that as a seperate issue at the moment.
so far I have fully warmed the engine up while sitting in the garage, twice since I have had the trans back in, (before I realized that my oil pressure is that high!) and started it for a couple minutes and shut it off here or there maybe 4-5 times. I have a Hastings filter on there hopefully better rep than Fram has now a days..... had a Wix on it from the PO.

I have the interior out at the moment, replacing the seat belts that the PO cut before I ever got the truck, also installed the NOS bottom driver side seat cover that I recently found on EPay, and replacing the headliner, tomorrow is the day that I will put that all back in,and take the truck out on its maiden voyage, I will probably put that manual gauge back in place of the sending unit for that maiden ride and monitor that, as well as verifying that the fresh trans works as it should....
down the road, I'd like to find a gauge pillar pod that will fit this series of truck if possible so I can add a mechanical oil pressure gauge T'd into the block and still run the factory gauge as well.....