Personally, I prefer turbo mufflers. Specifically, I use Walker DynoMax reverse-flows, specifically Super Hemi Turbos... they have large internal flow tubes and aren't particularly loud until you get on it. As I get older, I have more appreciation for quiet. I like the sound of Flowmasters, in fact the best-sounding muffled car I've ever heard uses 3" 3-chambers. But, I don't use them because they weigh so damned much (as do most chamber-style mufflers) and because they cause a lot of in-car resonance at certain speeds--the loud, almost buzzing hum of your eardrums--which I hate.
If shopping for turbo mufflers, the one thing you want to look at is the internal tubes. Thrush Turbos, for instance, may have 2½" inlets, but they neck down to 2" internally. Not good for flow. Summit has inexpensive mufflers with large internals, as do the aforementioned DynoMaxes (be they Hemi Turbos or not). Look for a note that says something like "inlet size maintained internally."
Also, though no one ever seems to think about it, any muffler with a fully-welded case is going to be heavy. Unless you're prone to putting your distributor in 180 degrees out, I've never really understood the concept of a fully-welded muffler. Crimp-case mufflers occasionally come apart in a backfire, but I've never seen one blow out any other way.
If you like that blatty glasspack sound, then I'd suggest Merit/Goerlich XCelerator, Edelbrock UltraFlo, or Borla XR1 mufflers. Straight-through design to get that farty tone, but no internal baffling or louvers. They start out fairly mellow but burn out in fairly short order and get loud. Those designs really resonate inside the car, too, and all are fully-welded monsters.
The exhaust system for the LeBaron will consist of headers, 3" X-pipe, necked down to 2½" afterwards with Flowmaster reducer cones, Walker 17748 Super Turbos, 2½" tailpipes into modified Merit 2½" tractor mufflers that look suspiciously like Hemi resonators, with 2½" turndowns at the bumper. Quiet, and it'll flow better than I need.
