I think a lot of the low wear on modern engines is due to premium materials and machining. I noticed a difference in wear between standard engines and HP, High Performance, engines. HP 360's and 340's would typically have less cylinder wear than standard 360's and 318's. The HP engines had moly rings from the factory, maybe lower tension? I know there is a difference in surface finish for moly rings. Corvette engines showed the same lower wear. I know that the HP 360's had different part numbers for pistons, rings, and valves. Maybe HP engine owners took better care of their motors? The guys I knew were always up for a challenge, so I doubt they were babied... Not discounting other factors mentioned above, but I did notice these things when rebuilding engines back in the day.
