Reviewed By STEVE C (Ruston, LA) Reviewed for a 2013 GMC Sierra —10/28/2014 7:00 AM
FLOWMASTER 10 MUFFLERS SOUND GREAT AND INSTALL EASY, AND A GREAT PRICE.
Reviewed By Andrew V (EAST WINDSOR, CT) Reviewed for a 2013 GMC Sierra —10/11/2013 8:04 AM
Shipped very fast i literally got an email saying it was shipped and a txtfrom my wife that it was delivered at nearly the same time. Noticeable better gas mileage i had the same muffler on my last gmc truck and will continue to use super 40 mufflers
Reviewed By Ray R (WESTERVILLE, OH) Reviewed for a 2011 GMC Sierra —7/2/2013 10:48 AM
I had a local shop cut the stock muffler on my 2011 GMC Sierra and had this installed. I paid 70 to have it welded on the stock exhaust pipe and could not be happier. if you have my truck you will need the 3" center inlet with 3" offset outlet. There is some resonance inside the cab but nothing crazy that will disturb your conversation or phone calls. could not be happier with the delta flow.