I'm guessing #13 is an aftermarket bar, but there is an important difference between the shop drawing I posted of the EARLY bar, and the photo in 13
The early bars, which mount below the K member, have the LCA tabs on the BOTTOM of the LCA, as yours are
The late FACTORY bars, which thread INSIDE the K member, have the LCA tabs on the UPPER side of the LCA, more similar to #13. Hard to see, but those LCA brackets/ tabs appear to me to be aftermarket.
Post #15 also shows an early, "low bracket" LCA
