Zinc Rich Oil for Flat Tappet Cams

I find it funny that no one ever argued the point about ZDDP until the government started mandating its reduction. lol
To, the flatten cam lobes on the sbc's (especially 305's) helped accelerated those arguments, along with some poor ole' engine builders that hadn't a clue and lost a few rebuilt motors due to cam failure..….
Oil companies certainly didn't make it a front page announcement when they pulled the zinc from around 1200 ppm to about 600 ppm to stop plugg'n up catalytics . Stiff valve springs on a new engine just were killed by it.