I would check to see how the oil hole in the lifter body is clocked relative to the galley passage and how the exhaust lifters are clocked. It may be possible that the bore is tight enough and not getting around the body of the lifter to the oil hole. Maybe the intake lifters were assembled 180* out.
The holes are offset and pick up oil from the gap between the lifter body and the bore on the intake side........the exhaust , which isn't offset , is " normal "
I have had a few people tell me that this issue isn't uncommon. Ryan J says run the drill for 1/2 hr. or use Brad Penn assembly lube liberally on cups and tips and once you start it up , it will be oiling very quickly.
This pesky work thing has kept me away from the garage for the last week , but I hope to get back in there this week end so I can run the drill and scratch my head some more. lol