I can't seem to find a good vid of what I mean... but I'm sure someone here knows!

That tinny exhaust sound some old muscle cars have... is it the solid lifters? Is it in the headers or exhaust?

Here's kinda what I mean: http://www.youtube.com/watch?v=w_lppD4z4po

 

you want it to sound sort of like a deisel. i think it might be the cam.

 

Yeah, I guess that's sorta the idea. Someone on another forum said its the headers too.

 

I've always associated that kinda loping sound at idle with a more aggressive cam, which would then be amplified by headers and a performance exhaust system.