Mopar did and still does rate horsepower at the flywheel. Around 72 all the manufacturers were required to rate them with an SAE net system which still measure the power at the flywheel but included all the accessories (water pump, alternator, p/s, etc), intake and stock exhaust. Prior to 72 they did what ever they wanted, headers, no accessories, non stock air cleaners, what ever gave the number the marketing boys wanted.