Product Details Home > Product > Product Details Products Details MBRP 4″ ALUMINIZED FRONT PIPE|2001-2004 GM 6.6L DURAMAX LB7 Part Number: SKU: GMAL401BKSJ Categories: 2001-2004 6.6L LB7 Duramax, Downpipes Call us now for our best price (574) 349-4354 Product Description Extra Info: MBRP Exhaust 4in. Front-Pipe w/Flange; AL MBRP Exhaust Installer Series, Front Pipe.