Always wondered if that was merely a coincidence, or if Cummilong was making a competition point.
Back in those times, Cummins was selling horsepower, with BIG price jumps between their product offerings as you went up the ladder. Which meant, the price gap between an NH-195 (672 motor) & the NH-220 (743 motor) was worth a year-at-the most suffering with a little less power, before correcting that at 1st in-frame.
As I remember, the liner inside-bore was the only difference, other than turn the wick up just a little on the PT pump. So, at least at Hastings Motor Truck Diamond-T in Nebraska, Everybody that bought new, bought a 195, & at first in-frame overhaul (around 100,000 in those days of oil bath air cleaners & oil that could hardly tolerate itself, let alone any trace of antifreeze), installed the 220 liners & pistons.
And in that era, I'd always heard the Mack Thermodyne would get 7 mpg easy, while Cummins struggled to average 6 (remember, this was on 4-axles, 60,000 lbs.)