They are different lengths for B13 and NX
overkill engineering motorsports is a good choice if you want to just bolt on a whole system.They have more choices for mufflers,etc.
If you prefer to build your own system,try a piping kit from VRS.Thats what I am doing,because I am using two resonators and a vibrant muffler.
VRS has been making mandrel nx exhaust for years...get it from gofastdepot
Go Fast Depot
I just ordered a 3"piping kit for my NX last Friday
I can wait to get this loud ass side exit off the VE