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FYI- much of the hot-rodder paranoia about ZDDP on older flat tappet motors is baseless, especially when you are dealing with a daily driver slant six. Unless you are building a very aggressive motor with high return spring pressures and aggressive cam profiles, you can just run regular motor oil and be happy.
I see you found the article I wrote documenting the differences between mechanical and hydraulic valve trains. When we broke in the "new" (reground) hydraulic lifters in my brother's engine after we swapped it to a mechanical cam, we used straight 30 weight for the break in and then switched to 5W-30. No problems ever since, and it has been over a year.
On a hydraulic motor there should be a fairly steady flow of oil out the tips of the rocker arms. If you are using the original rocker arm shaft and the original head, there is only one way to install the rocker arm shaft due to the stepped rearmost rocker shaft bolt. If the rearmost bolt went in then the shaft is oriented the correct way.
I do agree that its almost pointless on a street engine, but at least for break-in its good to have the extra insurance. I also used a conventional 30wt with the comp cams break-in additive. Then a conventional 10-40, and now running royal purple HPS 10-40 (no not necessary still but I apparently love spending money lol).
A hydraulic cam engine needs less protection than a hot rod engine, but some a lot of our slants are mechanical and I do feel they benefit a little from the extra ZDDP in the performance oils. Extra protection is extra protection, doesn't matter if its a econo-box grocery getter, or a full blown drag car, protection is protection...