Finally talked to someone at Freightliner.
Told them what I needed. He looked it up and said the because it's a RV. I have to go to Fleetwood for the tail pipe. Freightliner supplies the running gear and chassis. After that, Fleetwood makes changes to fit the RV. And the tailpipe is one of the changes.
Called Fleetwood. Open Monday through Friday. 8 to 5 EST.
Go on their website. Filled out the information they wanted. Hit send. Reply back was, We will get back to you during business hours.
This fcking virus got to go!