<<Not much of a surprise, since the M100 was designed in the 1959-1962 time frame (without computers, lol) and was VERY powerful for it's displacement at the time. 300 hp, 400 ft/lbs torque in 1963 on 6.3L was HUGE. It gave the 600 Pullman 0-60 times of around 11 sec and a top speed of 130 mph, no slouch! Installed in the 300 SEL 6.3 it gave 0-60 times of 6.3 sec, top speed 130 mph in 1970-72, the fastest production sedan built at the time, beat out any of the big block american iron by a handy margin at much less displacement (360 ci vs 455 or 500!)>>
I was OK with most of this right up to the end. My '63 Corvette's 327 CI engine produced a claimed 300HP with less displacement. And with pushrods and a carb, yet. That is not a "handy margin." And I would guess the Chevy engine was more economical and far more reliable. BTW, the data I've seen shows the 6.3's top speed higher than 130 but not 140. These days most modern cars that aren't Saturns or low end Toyotas can beat that. RLE/Seattle