I have no LS1/LS6 specific information to offer. Generic:
Special additive packages to protect during break-in are used on some engines.
This is much less of an issue with roller cams. Much like roller cam race engines, most of it is just seating the rings before you do power pulls.
Concentrated lubes used during assembly will also end up in the oil and augment the additive package.
The moly-disulfide paste used for cams, etc can clog the oil filter if used to excess. That's a reason to change the oil soon after break-in with an engine where you may have used a bit much "just to be safe".
I suspect the LS1/LS6 are run-in at the engine plants.
A certain factory's 5.0 was run-in with natural gas (not gasoline). Anyone know what the factory run-in duration is for the LS1/LS6 before it gets put in the car?
If they were to run-in with gasoline, there would be problems with gas fumes when transporting the engines. And natural gas won't dilute the oil on the cylinder walls, even if the engine is 'flooded' due to a spark problem, etc. I don't recall how long the 5.0 was run-in for, or how much of the break-in gets accomplished at that time.
I actually wonder if most of the 500 mile break-in on the Z isn't more for the powertrain than the engine.
If there is interest, I can find out more specifics from my brand X sources. I doubt GM is much different. But it would be better if someone could post the specifics on the LS1/LS6 instead
