Hope you have better luck then I did. If you find a place great, but dont get ripped off. It may be cheaper to just buy the pieces yiu need. I built my own y pipe kit using 6 inch exhaust pipe for 260 bucks. 10' stick and 3 6" elbows.
Ya i think thats what im going to end up doing, tried peterbilt they said use flexpipe not a big fan of flex pipe gonna be hard to peice angles together need a tight 180
I know there was a place in Muncie that a friend of mine used to go to other than that I don't know of any one you can buy prebent sections at truckpro at Thompson and Harding in indy