The heart of any Turbo system is the Manifold and the Turbocharger. These form the basis where the rest of the turbo system is built around. Turbo manifolds have only one, but the most critical purpose in turbo systems, and that purpose is to expel exhaust gas into the turbine of a turbocharger as efficiently as possible. There is no match for power and performance for tubular stainless steel manifolds. Tubular manifolds are made up of runners coming from each cylinder, meeting up at a collector. Tubular manifolds yield a higher efficiency rate, as each runner is generally the same circumference. This allows for a much smoother flow of exhaust gas to the turbo. Replace for 66-95 Chevy / GMC 366, 396, 402, 427, 454 Engines