I have been thinking about what kicked off muscle cars, and caused manufacturers to go all out making cars that went as fast in the quarter mile as they could.
The first was the Ford flat head V8. Sure, it wasn’t a high performance engine, but it started America’s love with the V8, and started the aftermarket performance industry in a big way.
The other thing that kicked off the horsepower wars was due to advances made during WW II. The ability to make low cost high octane gasoline, and advances in engines that were learned.
The high octane gasoline allowed higher compression ratios that allowed more horsepower. Starting with the Old Rocket engine, and the 331 Cadillac and on from there to the engines like the Small Block Chevy and the first gen Hemi.
As the 50’s went on, horsepower levels went up and up. Of course if manufacturer A has X power, manufacturer B wants more than X. That set up the engines for the muscle car era, but the cars they were in were still in large expensive full size cars.
Then drag racing started to get more popular, and those large powerful engines started to end up in lighter smaller cars.
Then someone at Pontiac got the bright idea to put a powerful engine into a flashy midsized car marketed towards younger people, and the GTO came to life and the rest is history.