There is no direct pressurized source of lube for the cam lobes. The LIFTERS... YES. But oil will follow the path of least resistance (around the lifter grove and up to the valve train) and you get basically a weeping action around the tappet bore.

Splash lube is any method of providing oil sans a gallery or dedicated feed path.

Cam manufactures sell additives.. OF COURSE THEY RECOMMEND $15/qt mystery goo. Saying that they recommend it is the biggest issue in a rational discussion... no one READS or RESEARCHES they simply buy something.

Here's the GM Crate motor break in procedure.. these are $3-5k motors:

http://paceperformance.com/p-3978-engine-start-up-procedure.html

Here's the money shot:

Quality 10W-30 or 10W-40 Oil is recommended for GM's Performance Crate Engines. Most Stock Factory replacement engines use either 5W-30 or 10W-30 oil.

NO MYSTERY GOO!!!!!!!! Use off the shelf oil for GM FACTORY CRATE ENGINES!

Why not demand GM EOS? Because you don't need it.

So, I have shown that GM crate engines do NOT REQUIRE ZDDP additives.

If you like, I'm sure I can find something on GM letterhead... but we both know that's not requires for stock/warmed over motors.