Premium M8 55mm CNC ported black manifold

Fits as a direct replacement upgrade for the standard 55mm manifold. It is a better, stronger and a more heat resistant replacement for the stock plastic (polymer) manifold. Made of T6 heat treated cast aluminum that is CNC machined on outside, but also CNC machined / ported on inside, for the ultimate in high-flow characteristics. Adds 3 to 5 horsepower and up. Especially above 124" the stock manifold becomes a restrictive part. Complete with a rubber O-ring seal. Easy to install, re-using all stock parts. OEM replacement reference 27300121. Note: For replacement O-ring seal see 974061.