Introducing the ultimate solution to your engine's exhaust problems - PDI's Big Boss Exhaust Manifolds! Our manifolds are designed to maximize exhaust air flow, reduce turbo lag time, and cool exhaust temperatures. With each port analyzed and tested for balanced flow to the turbocharger, our manifolds produce an impressive 20% air flow increase over a stock manifold, cooling exhaust temperatures by 75-100 degrees. But that's not all - PDI manifolds are also a key component in maintaining the best exhaust pressure to boost pressure ratios, providing potential for increased fuel economy. And with our superior grade of High Silicon with Molybdenum Ductile Iron (HSMD) material, you can rest assured that your manifold won't suffer from warping, cracking, or center divider failure from heat erosion. Upgrade your CAT engine with ease - our manifolds fit most engines with serial number prefixes 5EK, 6TS, 1LW, 1MM, 6NZ, 7CZ, and MBN. And with our 3 Year Unlimited Mile Warranty, you can trust that your investment is protected. Don't settle for a subpar exhaust system - upgrade to PDI's Big Boss Exhaust Manifolds today!