Flow-tested ported exhaust manifold eight hours of grinding has been done on the inside of the manifold. The ports reshaped and the rough edges are removed. When an increase of 110 cubic feet of air per minute (CFM) is obtained, the engine will gain ¼ mpg. The average improvement to each manifold is 120 to 160 CFM. Once the porting completed, the exhaust manifolds are then Jet-Hot coated to withstand temperatures of 1600 degrees, reducing friction, keeping heat out of the cast iron, & allowing more exhaust heat to travel to the turbo. The engine breathes better & truck will run more freely corrosion is reduced, also helps to keep the heat inside the manifold, helps to make the turbocharger more efficient. improvement of 25 to 35 horsepower will be realized, you should gain ½ gear on the hills.

*Manifold part # needed for Cats and Detroits; located on manifold