by doing the X-pipe it sticks more to the original stock set up compare to the straight pipe. My 05 4.4 has the x-pipe mod and I really like the sound, not too loud and yet not like the stock.

I took a look inside the resonator after it was cut off. I noticed that when looking down the 2 pipe, one pipe has drilled little holes that takes up half of the resonator length wise and the other half of the pipe is solid.

The same goes for the other side but the one of the pipe has little holes on the top half and the other pipe has the holes on the bottom half when looking for down from one side..