2011-2015 GM 6.6L DURAMAX LML MBRP GMCA427 3" TURBO DOWNPIPE (50 STATE LEGAL) 2011-2015 GM 6.6L DURAMAX LML The MBRP GMCA427 3" Turbo Downpipe eliminates the restrictive factory downpipe in your 2011-2015 GM 6.6L Duramax LML. Featuring a mandrel bent aluminized steel construction, the MBRP 3" Turbo Downpipe provides a... MSRP: Was: Now: $254.99 Add to Cart The item has been added