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

I have noticed that Mopar Big Blocks have a different sound to them compared to Chevys and Fords. I don't know how to describe it, but there is just some sort of tone difference, maybe it's just me I dont know, but it seems like with open headers there is a real noticeable difference. They all sound good bit MOPARS just sound different, has anyone else noticed this, or is it just me, and if so what causes the difference?