Buddy gave me this crossover tube he had welded up back when he had an NB1. Little bit of massaging and it fits my NB2 just fine. Throttle response in the low-mid RPMs seems a little different, butt dyno says I have a million more horsepower and will absolutely decimate a Bugatti Chiron, and my induction noise is a little deeper, which is nice.
Stock crossover tube.
Replacement is about a half inch larger in diameter and lacks the resonator section and ribbed portion, instead having a flex coupler.