I just base my opinion on experience as a younger man..I had a 72 Road Runner with a 400 4 speed in it back in 1979...EVERY and I mean EVERY 383 I ran against was no match for my car..Especially in a Charger body...Then one day I went up against a 68 Road Runner with a 440 and we left even but that dang car acually lifted up both front and back and launched like it was shot from a gun...I was amazed...Another car that smoked me was a Torino with a 428 that could smoke the hides at 40mph...Cool memories as a kid...But all those races left a bad taste for anything with a 383...In a Dart maybe but thats about it...Gimme the 440...
The 72 RR/GTX I have now has some seriously sweet stock power..From a 5 mph roll I can stab it to the floor and it will roast em on into second gear until I let off..I love these old cars..