I like the sound, especially the sound byte of the '60 Caddy. Take some time to look around the site, they have all kinds of videos and sound bytes to listen to. I the size is right for the truck stacks many of us use and I'll bet the sound would be awesome resonating inside the big pipes. A couple of the videos were especially great...one of a reworked flathead, the other of a yellow roadster. The roadster only has the backend showing sitting in a garage, but when you hear him crank it up and crack the throttle there's that unmistakeable whine of a blower.
http://www.portermufflers.com/