2001-2016 GM 6.6L DURAMAX HIGH FLOW RACE EXHAUST MANIFOLDS & GASKETS20012016 Duramax 6. 6L High Flow Race Exhaust Manifold Kit Improve flow Reduce backpressure Increase performance Upgrade your 6. 6L Duramax with our high flow race exhaust manifold system, designed to replace the restrictive factory manifolds found on 20012016 trucks. This setup improves exhaust flow, lowers EGTs, and supports higher horsepower builds whether youre towing, daily driving, or running a full performance setup. High Flow Race Manifolds