A note on Rotella having ZDDP acceptable levels is true. They are on the decline also due to Federal pressures because of claimed environmental damage.
Also is high in detergent levels ( disbursement levels) which does exactly that, reduced and depletes the ZDDP levels in the oil. No problem as long as you keep your oil change cycles  shorter. 
What ever oil u choose keep up to date on their  website for the levels. Around 12% is what u want. 
Also excessive amounts are damaging also. Can cause scoring. 
I prefer to use  a 4 oz bottle of ZDDP at oil change and you can use today's SN rated oil if u choose. 
I don't totally trust manufacturers claims of levels anyway. 
And use a quality breakin oil during initial run.