> It isn't a 1942 Plymouth.

Actually, the Plymouth Six is about the toughest engine ever made. The Israeli Army was still buying 1934-1960 Plymouth Sixes for new trucks in the 1970s, because they were so unkillable. Peak power was around 3,400RPM, but they will cruise above 4,200RPM for years. My brother has a '42 that has never been touched except oil change (occasionally) and plugs and carb gaskets, runs good: a bit rich, but strong.

A friend of the family flew a 1934 Plymouth engine. Low cost airmail transport. It flew fine, roaring along at full power. It finally let him down when he had 500 pounds of mail and 600 pounds of extra fuel coming down the coast of Alaska. Even then, it let him down gently: he was able to go bang between two rocks and walk away. And odds are he wasn't changing the oil as often as he shudda. (And pre-1980 oil was much worse than modern stuff.)

> And it's not a shitty Ford

Hmmmmm..... I'm an old Ford guy. A properly prepared Windsor will rev to 8,000 RPM and hold it for days. In 1963, Ford took a trio of "stock" Galaxies to Daytona and held them at 100MPH (about 80% of full power) for 100,000 miles (6 weeks of 24/7) without failure. And yet: I took my '79 over 3,500RPM, once, and it quit. A 2-cent weight came loose in the distributor, jammed it, broke the cam gear. A rebuilt dist was only $34 so no big deal except I had to get towed home. Ford's big parts are 99.9% tough, but you really have to check for "minor" flaws. Honda builds them right, even the little parts.