hi, I assume you dropped the oil pump to install the new pickup tube??
when you bolt up the pump, some times the pump will hit the rear main cap bolt head and **** it. causes a gap between pump and cap flanges. the mopar race book talks about this problem. If this is the case, you had no pressure. mopar says , might have to rotate that bolt some to clear pump so it will mate up correctly. I have seen this happen before, one guy tightened his down and broke the pump base!!! there is not a lot of room there, just food for thought!!!