although his pressure is pretty low on that reading, i sort of have to dissagree with the comments stating thicker oil won't change the pressure (reading).
ever since i had this '94 with the 4.3ltr V-6, it would always run 45-55 psi range, i pretty much only used 20/50 weight oil, as we lived in Phoenix, extreme heat conditions, during winter months we used 10/40.
Just recently, like last week, i switched to a full synthetic 10/30, thickest i could find. While driving it's still up in the 55 or so range, but at stoplights it drops to about 25(ish) no noise or anything else out of the oridinary, just that thinner oil is all that changed.
This is also a high mileage motor sitting at about 225k miles.
Personally if this is a new motor you're working on, i would get a different pressure reading off a better quality gauge if you're currently using the stock one, even the oil pressure sending unit could be bad.
Had this issue with my burb awhile back, always read high, until i changed the switch out due to a leak, and then was back down into a normal range.
