I have replcaed dozens of oil cooler lines. Mostly on the 4.3L Jimmy, Safari, etc.
As sdime says above the original lines DO all leak to some point, but I have yet to see a set of the GM updated lines leaking.
Like I said I have replaced dozens and we as a shop have replaced many dozens, but we have not seen a new set leak yet.
The only way to tell the difference is that there is two "crimps" on the old style and three on the new where the rubber is crimped into the fitting ends.
We have taken a couple apart and have found that not only the new crimp, but GM has added a longer male end into the line as well as a (neoprene?) sleeve over the end of the line to be crimped.
So I'd suggest, when replacing the lines, you use the new style from GM.
Just my
Hope this helps.