B16 and B18 series Cast Manifold. High quality cast turbo manifold for those who are piecing together their own turbo kits. The manifold and turbo are the most important part of the turbo system, so do not skimp on these components. Spend a little extra money for the insurance and warranty that this manifold will last and not crack. Do not worry about whether your AC and power steering will work with other manifolds on the market, this design has been around for years, is AC and PS compatible, and use by some of the top names in turbocharging, Turbonetics, Drag, and RevHard! Manifold will work with any size turbo T3, T3/T4B, T3/T4E and up to the Turbonetics 60-1. HTreadstone manifolds are cast using a high ductile silicone based iron adhering to a strict ASTM casting standards. These manifolds are very durable and will withstand all the heat and vibration you can throw at them. Our manifolds casting exceeds OEM specifications and now come with lifetime warranty against cracking(veiw tech page for additional info on warranty). All of our manifolds incorporate external 35 or 38mm wastegate, and either T3 or T4 standard turbine inlet. All internal surfaces are cast smooth for high flow and low surface friction.