Dieselr Aluminized 4" Cat Back Race Pipe | Cab & Chassis GM 2500/3500 6.6L DURAMAX LMM 2007.5-2010The Dieselr Aluminized 4" Cat Back Race Pipe (2007. 52010 6. 6L Duramax LMM) is built specifically for GM 2500 3500 Cab & Chassis trucks that demand performance, durability, and a perfect fit. Constructed from 4 inch heavy duty aluminized steel, this system improves exhaust flow, lowers EGTs, and delivers a deep, confident tone built for real world diesel work. Every Dieselr system is mandrel bent for smooth, unrestricted flow and precision welded to