Craigslist
Gary, I see people selling their stock exhaust systems all of the time on Craigslist. Often for $100 to $200 complete front to rear. You could also list your system on Craigslist and look for someone that wants to trade their stock system for your modified system. Additionally, you could look for a 2006 LBZ air filter assembly. People put on aftermarket air filters and take whatever they can get for the original air filter. If you look under Duramax parts you won't believe what you will find for sale.
I am glad you found the overheating problem on your truck.
Good luck
John
*2006 Chevy, 3500, 4X4, DRW, (LBZ) D/A, CC, LT, 252K Miles, 19.5" Wheels, Mag Hytec Transmission Pan and Differential Cover, SS Grill Guard, Racor 2 micron aux fuel filter, 100 Gallon Aux Fuel Tank, using Edge Evolution, Predator Diablosport, Kennedy ECM tune, Fitch Fuel Catalyst.
*2006 Four Winds, Dutchman, 36', RV, D/A, 5500 Kodiak.
*1993 Harley Davidson, Turbo charged, Springer Softail.
*2007 Pontiac Solstice.
*2005 Jeep, Liberty, CRD (diesel).
*Full-timing in USA, see America first.
BUY AMERICAN or CANADIAN, NOTHING from CHINA .