That horsepower rating was measured at the crankshaft without any power loss taken into account as the rear wheels were driven. In those days the U S auto companies were in a Horsepower rating war. Real SAE HP rating was about 325 to 330. That was still enough power to burn up those skinny 15 inch tires pretty quickly though.
Well people are so used having slam the door,hood, trunk to get them to shut on the New car's ‼️ they have forgotten how to just shut them on the good old cars ‼️ that was built with pride ‼️ that no one seems to take in there job now a days ‼️ that is the reason everything is made so disposable now 😒‼️
