It was this one:
https://www.oreillyauto.com/detail/b...=50-1007&pos=0
(Oreilly, not Autozone!)
I bought several lines for this 71 job from inline tube, but bent them myself on a different 66 C10 project. Even if you bend your own, it's sometimes worth buying at least the MC to distrib block lines simply they are so short and difficult to get just right/looking right. When I bent my own, I used the regular old oem steel line type (not stainless). THey were easy to bend, and I didn't really like the green tint of the new type. It was actually kinda hard to find regular steel lines...
Here's what the above part # looked like installed.