Muffler choice

[Carlwalski]

Yupe, mine too is rubberized, not sure what you call it exactly but it's good stuff for real driving cars.
The dynamat works wonders. When I drove my Dad's Cuda it was loud with no dynamat and I myself prefer it that way.

The 71 will have just carpet/underlay/felt and that's it. 

[chrisII]

my duster has hooker headers into 2 1/2 pipe with hooker aerochambers and turndowns. they have there own sound theyre somewhat quiet, but bark when you hit it

[BIGSHCLUNK]

I think another consideration has got to be the motor your runnin' a Hemi vs big block vs small block all have distintive sounds. And in head an cam configuratione ect....