I vote Loudmouth, even though my car has true duals.

 

mufflex? or did you have it custom made?

 

The I-pipe in mine was from a Mufflex system, but the rest was custom made. I wouldn't go 4" for your setup though. Spintech makes a 3" catback for 98+ cars that could very easily be adapted to an lt1. The price is somewhere in the $300-400 range. Their mufflers just sound sweet in general, and unique for that matter. It's got that chambered throaty growl, but with hardly no interior resonance. Even with my 4" setup it's not bad at all inside the car. I highly recommend them. And as far as power, I gained little to nothing by going to open headers at the track.

 

I went with Edelbrock Catback to be different from everyone else, plus it is very reasonably priced. It also has the sound of old-school muscle.

However, I'm not very fond of the tips. They kinda look like oversized V6 tips.