oil pressure question

RustyRatRod said

Not anymore. Since a few years back, none of the diesel oils have the high levels of Zinc they used to because since 2004, diesel trucks now have catalytic converters. So if you use diesel oils for high zinc with a flat tappet, be warned. It doesn't have enough zinc anymore.

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Yes, in general diesel oils have less ZDDP now than 15 years ago for the reason you stated. But I'm not speaking of diesel oils in general, but specifically Shell Rotella T6 5W-40. Others may be similar.
T6 5W-40 has around the same amount of ZDDP as many of the old SE, SF, and SG oils did back in the era of the OEM flat tappet engines. It has about 30% more than is allowed in modern API SN and ILSAC GF-5 oils. In other words, enough.
If the furyus2's engine has open spring pressure above 350 PSI, and is living at high RPM, he needs racing oil, and everything that comes with (and without) it. My impression is that it's a street engine, and my recommendation stays the same. Readily available, relatively cheap, and better than any oil on the market when 440s were new.