Exhaust.... Stacks?
I saw another Dodge with straight pipes the other night. It wasn't as loud as the 7.3, but it still sounded pretty good. I also saw a '94 F-250 N/A Diesel with straight pipes last night. It sounds stock at idle, but when that feller took off, it sounded like a regular gas engine with straight pipes except for the compression/combustion "trademark of a diesel" sound.