Engines also wore out faster before overdrive.
The stock 318 in the D100 I mentioned before would not keep up with traffic with the pedal to the floor.
lol, that wasn't it's job. Imagine that same ride with a /6. Wee.
As for wearing out faster, more likely it had to do with the rings used and the oil formulations than OD. I still have the 318 out of my 87 Diplomat, 200k+ miles, bores look pristine. Moly rings, good oils, regular maintenance. No OD. back in the musclecar days, well oils sucked and cast iron rings.