If you're getting old and feeble like me, slap one of these in your valve cover and get all of that oil inside the engine rather than rust-protecting the side of it:
https://www.ebay.com/itm/10-14-LS3-L99-Valve-Cover-Oil-Filler-Tube-Extension-NEW-GM-2-TAB/131665757630?hash=item1ea7e405be:g:8I0AAOSwd0BV7Cwm
By the way, check to see if the tabs in your valve cover are at the 3 and 9 positions. If they are at 12 and 6, then you'll end up 90 degrees out of phase. Don't ask how I know.
(You "digital" people won't be able to figure this out!)