Why do Mopar Engines Have a Different Sound From Chevys and Fords??

i can always tell when a 440 has high compression especially with a 4 speed .....under load it has a high pitch ring to it ....the lower compression ones have a deeper tone that does not go as loud ...also on a 4 speed you can hear the compression in between gears when you unload it by putting the clutch in kinda:

RAAAAAAAAbaaaRAAAAAAAAAbaaaRAAAAAAAABaaUmmmmmm :D