That's one of the high pressure lines at the A/C condenser. I think it's the suction line. The torque spec for each of those line bolts is 15 Nm / 133 lbs-in. Those images are pretty zoomed in, you might be best off to try to match them up with images at RockAuto or one of the many FoMoCo online parts sources. However, based on the appearance of that seal, you may just need to replace the o-ring seals on the fitting if it doesn't appear that the line itself is leaking. You're probably looking for Seal Kit DL3Z-19B596-B.
-Rod