I wanted to revive this thread to say I installed Sunroofcuda's 12" resonators into my tailpipes today.
When I first started it in the garage I said to myself well that was a waste of money. Took the car out for some driving and am super happy with the results. It isn't alot quieter at idle but it is less offensive. Where it really helped for me was driving around when your just looking to fit in. The sound is toned down a bit but the seat of the pants dyno feels no loss!
With a 512 TTI headers into the 3" x-pipe system with Ultra Flows and only running 3.23 gear the convertor was making it seem so loud to just cruise but now It's lost that loud bark making it so much more pleasant.
Ron