Chevy Avalanche 2006 Exhaust Headers At the Guaranteed Lowest Price! Doug Thorley Headers Exhaust, Mufflers & Tips In Stock Now. Read 38 Customer Reviews, Shop Online or Call 800-544-8778. Doug Thorley Headers. For the top selection of Chevy Avalanche 2006 Exhaust, Mufflers & Tips, choose AutoAnything as your trusted store. The Doug Thorley Headers will improve and personalize your vehicle. Avalanche Exhaust Headers by Doug Thorley Headers – selected by many auto enthusiasts in the top automotive discussion forums. Doug Thorley Headers for your 2006 Chevy Avalanche will deliver the results you are looking for! Doug Thorley Headers – Chevy Avalanche 2006 – Exhaust, Mufflers & Tips – Exhaust Headers.