The Protech Shorty Manifold for the QG18DE is constructed out of sch. 40 forged steel using the GTAW ( Gas Tungsten Arc Welding ) process. They are designed for the T3T04B/E, T28 Garrett/Precision, Turbonetics, and HKS compressors. Each exhaust manifold flange is ½ inch thick, port matched, deburred and polished for limited drag and ceramic coated. The head flange is segmented for thermal expansion. ***Call For Pricing***. All Pro-tech product's are intended for off-road use only, and prices are subject to change with out notice at anytime.