I always pull all the spark plugs before pre oiling and then turn the motor over by hand on the engine stand slowly while priming on all the motors I build and or assemble
As you already know all the LA motors have real issues with the pushrod to rocker arm angles so expecting all the lifters to oil all the pushrods and rocker arms at one crankshaft position is hoping for miracles, correct
Prime and rotate while priming and let us know your results