This is a first time build of an LS engine for me. I'm using a DART block. After putting the assembled short block in the car I put 3 quarts of oil in the pan, Then put an oil cooler bypass plate on with a fitting to attach a hose. I pumped 2 more quarts of oil thru the hose which should've primed the pump, galleries, filter etc.. I then stuck the hose from the bypass plate into the valley and cranked the engine with the starter. After about a second oill came out of the hose at pretty good pressure. I couldn't stop it by putting my finger over the end. So far so good. After putting heads on I was assembling the rocker arms and noticed that I could push down on the pushrods and compress the lifters. So I cranked the engine a few seconds and the lifters got solid telling me they pumped up with oil. Seems normal so far. Now on the valley cover where the oil pressure sensor attaches I drilled and tapped a hole to also attach a mechanical oil pressure gauge. So now the problem is when I started the engine I have no oil pressure at either the sensor or gauge. So maybe something is preventing oil to come up thru to the sensor. But another worry is I stuck my finger in the oil fill hole on the rocker cover where I can see and feel a rocker arm and it doesn't feel like any oil came up the pushrod. Any thoughts would be appreciated