Walker Exhaust has all the pieces:
https://www.walkerexhaust.com/find-my-part.html
Select your vehicle and then it shows you all the parts to make a whole system.
Walker 48111 looks like the main front pipe. Not sure how it fits. Found this webpage where a guy says he bought it:
https://lugnutz65chevystepside.weebl...chives/01-2015