Just watching a YTer put his LS truck motor together and he used light grease for the valley pan gasket(& others i think). I've never done gaskets on any LS or used these Metal Rubber embossed type gaskets really.

Clean oil free surfaces and Dry or Light grease/oil?

Got a 5.3 that I wanna go thru this winter. Was suppose to last winter but couldn't due to an injury.

 

I personally CLEAN the surfaces....and use RED TACK in the spray can on both sides of the gasket

side note....had a really bad oil leak under my car .....swore up n down it was the rear main seal.....found out in a tear down it was the OIL PAN GASKET......all the rubber had deteriorated and let the oil just flow out

 

Everything super clean and dry. I try to use brake parts cleaner on all gasketed surfaces to ensure clean and dry, with a clean lint-free rag, just before install. I don’t touch the gaskets themselves, leave them clean and dry…they actually feel a bit “greasy” to the touch when new, but that’s just the silicone or rubber in them. I do spray headgaskets with copper spray fwiw.
Doing it this way ensures a leak free build, as the gaskets are designed to go on dry. Front and rear cover alignment is critical, as is oil pan alignment with the rear of the block/front of the bellhousing. If you aren’t familiar with cover/pan alignment, do some research. It’s easy once you understand exactly what you’re trying to align the covers to.