No Replacement for Displacement (myth or fact)

One things have forgotten to take into account. The bigger the part the more wear and greater chance of failing. Vs a small part with less weight can move faster and do it longer with wear and less chance of failing. Example is that in racing (for extended time) a smaller motor with small parts (like a 4.6l v12 motor) with have less wear then a big motor (like a 408/416/426 sb motor) with its heavier parts and higher rate of wear. But it all really comes down to the valve train! A dual overhead cam design with 4 valves per piston can and will take more HP/Rpm/stress then a standard Pushrod based motor with two big valves.