A lot of you keep missing the 500HP AND 19-20 mpg part. I don't care about stock 318's/340's,360's,383's etc.... that did or could have gotten 20 mpg-ev.en still they would be the exception rather than the rule
Your Dad's bone stock Charger with a 360 had no where near 500 hp.
Oddly enough my father had that exact car when I was a baby, was yours blue with a white vinyl top and interior? lol. J.Rob