I had to replace that line last summer. As stated the line is part of a kit that extends through the blocks water jacket, out into the push rod gallery and feeds up to the rocker arms. I got the oil line replacement kit from one of our popular on-line venders here. On a scale of 1 - 10 I'd give it a 5 in mechanical difficulty and an 8 in access ability difficulty. It's a piece of cake if you pull the engine grin (j/k)
You need to drain the coolant, remove the large side cover and lay all over the drivers side fender to get the line installed and properly connected leak free. I used Teflon tape and it hasn't leaked in nearly 2k miles.....
Took approx. 4 hrs. I think I documented it but don't recall, others have tho...
So you'll need the oil line replacement kit, new side cover gasket, a valve cover gasket and any anti-freeze you cannot save.
As said, do it right and you won't have to worry about it for a long time.
Dave