89 ford 302 low oil pressure?

When it was rebuilt did the shop that did it check your clearances properly? If that cam and or crank were not properly clearanced you could get a low oil pressure. Try putting a thicker oil in it for now. I would try 20 W 50 in it and see if it affected the oil pressure. If it's a clearance problem you will notice a jump in oil pressure. Did you use the old pump in the rebuild? I hope not. Ware in the pump can cause this too.

those previous fords had low oil stress and with the miles you have this could tell the story, yet i could unscrew the sending unit from the component of the block, and screw in a instruction manual gauge which will examine the oil in pounds according to sq. inch, usually situations the gauge reads below the motor is, with reference to the suited element to do is pass to a 20 50 and upload a quart of lucas oil stabilizer, those 2 issues on my own will convey the oil stress up by using a solid 5 lbs, and the lucas will keep the oil stress from bottoming out as undesirable, the backside end bearings are unfastened, there won't be plenty left you're able to do, different than set up new backside end bearings, and upload a severe quantity pump, do no longer confuse this with a severe stress pump, severe quantity basically provides a quart greater oil because it circulates solid success, yet severe miles, is severe miles

Excessive clearances is generally the cause of low oil pressure after the engine reaches operating temperature.

sounds like the oil pump or pressure regulator is down

test it with a master gauge, it may be your dash gauge is not accurate, could also be faulty pressure sender unit