Filling or priming hydraulic lifters is a great way to bend pushrods when installing the rocker assmblies, not so good a way to properly fill them though. If they aren't filling up from engine oil pressure then lack of priming or filling them isn't the problem.
I would take the soft lifters out, disassemble, clean and inspect them.
They say there are no such thing as a stupid question. They say there is always the exception that proves the rule. Don't be the exception.
