With the engine assembled you should be able to remove the dizzy and spin the oil filter and see it pump up to the rockers. It is called priming before you end up with a dry start.
You may need to get a new oil pump. You may have an oil galley blocked also.
89 2.5 TBI, 4" RC lift, 1" Booms, SYE, Adams Driveshafts front and rear, Ford 8.8 with 4:88s, BFG 33X12.50X15, and a ton of other stuff.
AF Jeep Club Tail Number 184