WTF!!!!!

[Kalstar]

No oil presure. Started the LS for the first time with an oild gause hooked up and no presure. I founf the gasket on the pickup tube was off and laying in the oil pan, put that back on and secured it. Tested again, still no pressure. Removed oil sending unit and nothing pumping. Pulled valve cover all lifters collapsed with no sign of oil. Pulled the pan again and pulled the main cap (bearings perfect) pulled one head, cylinders perfect. I pulled the front accessories to get to the oil pump, noth out of the ordinary there either. I am at a loss. Were and why no oil presure. I got the oil pump to pump oil but is not getting to the top. What am I missing. Must be something stupid that I am over looking.

Thanx for the help.

Jim