I didn't miss it. It's not just the oils, but the combination of the oil, the wear inherrent in the blocks' lifter bores now, ingorance, production screw up (remember the flat lifter bases..) and the single largest factor... The cam lobe designs. You simply didn't have the rates of lift in a flat tappet cam back then. The ones that came a little close were MP's mushrooms and Ultradyne's specials. There were plenty of cam failures back then. But not in the volume (especially when you consider the percentages) you do now. Back then about 5% of cams failed due to break in or "issues" (my estimate anyway...lol). And that was 5% of everything that was V8s in service... Back when it was only V8s or straight 6s. Now it seems like the total number of V8 users is way down across the board, but closer to 25% or more fail. The snottier the rate of lift, the more likely it is to fail.