For some odd reason, oil info is hard to find for these G3s,
I personally think it's one of the better thought out systems out there today....
The oiling tricks are harder to find, not that there is a lot of them, not like the old school Mopar’s where every engine family has its special tricks to survive.
The Top end is feed separately (so to speak) but the lifters are feed at the same time, the passage that comes up from the main galley, between 1/3 2/4 5/7 6/8 feeds the MDS(and NON MDS) off of the passage that goes to the heads. Each set of 4 lifters is feed by it’s own passage and drains back thru lifter bore clearance.
The passage to the MDS solenoids is very small and hard to find,
Oil comes up from the pump hits the 1st main and then main oil galley above the crank and below the cam tunnel, feeds Cam Bearing #1 travels down the main galley feeds the 1st Top end passages and the 2nd Main and cam bearing, so on and so forth.
One of the things That I like about these engines is the lifters banks are separated in to 2 separate sets of 4 .
(Oil trick if you want to block off oil to the lifters you just block off the passage in the MDS hole where it taps into the head feeds)
Another thing I really like about these G3s is you can modify the oil system to feed more oil to the top end without affecting the mains and cam bearings.
Also if you have a catastrophic lifter failure it’s not going to drop oil pressure and wreck Main and rod bearings.
Oil from the Rocker's and pushrods feed the rocker cup, kind of over kill if you ask me but I was told it was designed that way to have a secondary source of oil to the lifters to insure that the bore was lubricated if there was an issue with the MDS solenoid
Now if these bright engineers didn’t straight cross drilled the 03-08 cranks they way they did there would be no high RPM oil issue.