Someone convince me to run ZDDP

[DT1]

I have been reading everything I can get my hands on about the benefits of running an oil with ZDDP in my SBC, flat tappet engine, but to date I'm still not convinced.
I hear horror stories about some engines only going 200 miles or less because of the lack of zinc in the oil.
According to what I've read, the oil companies took zinc out of oil quite a few years ago and didn't bother telling the consumer about it.
I hear things like: "Engines with flat tappet cams must have zinc for proper lubrication" and "You can't run zinc in a modern engine because it will ruin the catalytic convertor."
I own a 71 C-10, 67 Mustang and 56 T-Bird. I have always ran regular Dino in all of them. I restored the Mustang in 96. It now has over 60,000 miles on the engine. No Problems. I restored the C-10 last year and have already logged 12,000 miles. No Problems. The bird has 40,000 miles. No problems.
How about catalytic convertors? I have a 75 F-100 with a CAT. and I believe back then all oil had zinc in it. Why didn't the Cats go bad back then?
I'm not saying that oil in flat tappet cam engines wouldn't benefit from a zinc oil or additive. I just saying that I need more convincing from someone that really knows the story and not someone that heard it from someone, that heard it from someone...