Help - No Oil at rockers

The engine is a Series II 3.8liter NON Supercharged V6.
I agree the shop should stand behind it. Hes as stumped as I am at the moment. Over the weekend we tore the engine back down (New gasket set (OUCH$$$) what a waste). We found nothing wrong. Checked all the clearances of the crank, oil pump, balance shaft, oil pickup to the bottom of the pan. Its back together now and guess what - still no oil pressure. Its on an engine stand and the starter is attached to spin it. We did the petroleum jelly in the pump and nothing. Im still searching for an answer guys. Thanks

The engine was working fine with the exception that it was starting to lose power because it had 250,000 miles on it. The upper intake had sprung a leak inside around the egr tube. Since it had so many miles on it I decided to have it rebuilt for the warranty. Of course he put the old intake back on when reassembling it. I caught it before adding coolant. I installed the new intake while trying to get oil pressure. Nothing on the gauge. Nothing on the rockers. No spark-plugs in it until I get some pressure somewhere. Using the starter to turn the engine. We have primed it again with a pressure tank using the hole for the oil sending unit. Didnt want to run the bearing dry using the starter. I have always changed my oil at 2500 miles since I was 16 MANY years ago. Grandpa did it to me. He only had to polish the crankshaft there was so little wear on it. No we have no oil. Frustrating.

Thanks for trying. I decided that I would take the oil filter adapter off and check that the valve wasn't sticking closed or something. It was assembled exactly backwards - the spring was holding the valve over the feed port - No Oil doing that. Its supposed to be spring in casing first then valve, gasket, cover. He had put the valve then the spring. When it in backwards the pump cant pull from the pan. The oil in the filter I put there to help the engine prime faster. It was full after the pressure prime we did too. I have the motor back in now. I have 60lbs of pressure on the gauge. Took it a few minutes at idle to stop tapping but it finally did. I have to go thru the computer relearn procedures before I give it back to the wife. Runs really bad. It did the same thing when we redid the transmission last year. It ran poorly til the computer was finished relearning how we drove. Ive been arguing with him about that valve since we took it back out of the car. He insisted that it was done properly. I hate that I have to go behind a "pro". If I didn't want the warranty I would have done it myself. Time to button the car back up - put on all the shields and covers. Gotta do coolant bleed and power steering fill too.
Thanks Again Guys.

After 50 miles of in town driving the 3.8 was still running bad. I took it to a local NAPA Auto Center and had it diagnosed (350). It seems that "The Machine Shop" forgot to install the camshaft sensor interrupter (magnet $70) on the new timing gear. Ive learned that they will break when you try and move them over from the old timing gear unless your careful. We did not find any pieces in the timing cover or the oil pan at any time - so it was never installed on the new gear? Another $750 to fix at NAPA. At least I know that my timing interrupter and timing gasket have a real 1 year warranty. =)