The vast majority of cam/lifter failures in the 5.7 come from fleet vehicles with 100K+ miles. The 5.7 also outnumbers the 6.4 by a huge margin. There is nothing "wrong" with the design of the engine components. Materials and hardening on the other hand,
may be an issue. Like I said, the majority of failures are seen on high mileage engines. Early failures are likely the result of operator error. Not letting the oil reach peak operating temperature before racking the engine is one. Running the wrong viscosity is another. I'll have to disagree on the
type of oil. Running conventional oil in a Gen III HEMI would not be wise, especially in a 6.4 HEMI. Oh, you can do it... but, start racking that engine and you're going to cook the crank bearings. Oil brands can be an issue, as some do not contain enough "slippery" additives. Again, this would be of more concern with the 6.4 HEMI. By example, modern Harley Davidson engines run tighter tolerances compared to most big-twin engines. Oil weight and type are critical to proper performance and longevity. I've built/rebuilt enough of them to know. Tighter the tolerances = increased heat. If there is a
wrench in the works, it is surely the EPA. VVT, catalytic converters, 203 degree thermostat, 215+ degree fan setting...
Note: Issues regarding supercharged engines; I am not familiar with. One day, maybe.