I first got the Flowmaster Force II catback for My 6-speed R/T and did not find it much louder than the stock exhaust at idle or cruising, but it did change the tone... there was no drone either... At WOT it did wake up a bit...
I wanted it louder, so I ordered just the tail pipes from Flowmaster American Thunder catback to replace the Force II resonators since they are interchangable... Cost $150.00
Now it is loud and has "DRONE" from about 1800 rpm to 2300 rpm.... I am probably a little louder than the Americam Thunder catback since the Force II came with Super 44 mufflers vs the Super 40's for the American thunder...
The tone or sound is the same with both catbacks.. just the loudness changes and you get "drone"...
For those with the Auto R/T that have the American thunder catback and like the tone, but can't take the drone...save the money and just add the resonators instead of buying another catback..
As for Me, I'm torn between the two... I like it loud, but the drone can get annoying... I'm keeping the resonators just in case... I might experiment by changing out the Super 44's to something else to tone it down just a bit

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