After searching high and low through countless video clips, I went with Flowmaster AT Classics (part #817460) for my new '10 GT and left my factory H pipe in. I learned quickly that microphone location and quality of mics used produces severely inconsistent sound clips so I had to roll the dice. For this system, Flowmaster advertises a very deep, throaty sound going back to the 5.0 glory days....... and they hit it perfectly. The techs in my shop can't believe a simple bolt-on axle-back install could produce such a deep sound. Flowmaster must have gone back to the drawing board on this system to bring customers back to their product. The fit is spot on and muffler construction is vault-like so there isn't annoying resonance through the floorboards and such. In addition, they are ALWAYS deep no matter where you are in the rev range but 
aren't annoying.....however, once 3500 rpm spins up, the heavens open up. It seems like my power curve has been shifted "up" slightly in the rev range and now the motor pulls considerably harder from 3500 on up. One thing to note, with my 3.73 rear end, the power/ torque felt slightly stronger below 3500 BEFORE the Flowmasters but again, that's my initial impressions driving for just one day. I think I'll reset the ECU this morning and then report some mileage numbers and other info next week as I drive more this weekend. Peace.
aren't annoying.....however, once 3500 rpm spins up, the heavens open up. It seems like my power curve has been shifted "up" slightly in the rev range and now the motor pulls considerably harder from 3500 on up. One thing to note, with my 3.73 rear end, the power/ torque felt slightly stronger below 3500 BEFORE the Flowmasters but again, that's my initial impressions driving for just one day. I think I'll reset the ECU this morning and then report some mileage numbers and other info next week as I drive more this weekend. Peace.
we wanna hear it
