Which is better 4" or 5" (w/ Muffler)

[UNBROKEN]

Doesnt affect performance at all. Zero increase in EGT's or any other negative effects.
It's only job is to kill drone and it does tha better than anything I've seen so far.
Look up FTE Diesel.
Wally goes by Jackthebear3 on various forums.

 

[PatriotHauling]

.... [LINK REMOVED] Walker 21470 Big Truck Muffler

sound clip only one I could find

Here is my old BTM
http://www.youtube.com/watch?v=kB1Y7BzgNrM

And my new 4" MBRP
http://www.youtube.com/watch?v=hwBtD4zzvPU