I also have the lifter noise in my L77, I did mention it to Holden a couple of times when I got it serviced,
and they said its normal for AFM do that.
So I haven't bothered, but its a bit worse now, Its not so prominent if you take the engine cover off, but you can still hear it.
Worse in the mornings, when you just leave home, and when moving off with the traffic, quieten downs when it gets up to temp tho.
I had a mate of mine that worked at a Dealer years ago, [will remain nameless] and he said, sometimes you may have to put a litre of gear oil in, to thicken it up a bit, he said it wont harm it, just shuts the clatter up.
I did purchase a Stethoscope from Supercheap, and listened carefully, have put it down to one of the either DOD cylinder on the drivers side.
I figure, best I just get a new set of Lifters.