[William]

Nope. But he obviously knew they were rated @450hp at one time and felt justified in using the number in his marketing info.

Those were the old gross HP days anyways. Add the "as-installed" equipment [fan, alternator, etc.] and you have net hp, the real number. I recall maybe 10 years ago one of the mags did a feature on a L72 clone build-up and it just made the 425 number. Maybe the 450 was never real.

I'm aware that with today's rings and oil [and maybe cement pumped through the ports] an L72 can do better.