I have the TTi's on my 340 Challenger and they fit great. They were expensive to buy, but they fit snug to the bottom of the car.
Some cars that have the low hanging headers you can see them hanging down when walking up to look at that car. The TTi's you have to bend down and look under the car to see if that car has headers or not. I did have TTi send me the 6/7 degree angled reducers to make it all fit nice though. The below picture shows the stock reducers before the swap which makes the exhaust pipe go downward towards the ground too much for my liking.