The original Inlet Manifolds are not only a poor design for air and fuel flow but they are also becoming expensive to buy second-hand.
This Free Flow manifold helps the engine to breathe and reduces the turbulence in the manifold by improving the air to fuel ratio balance flowing into the engine. This produces a flatter torque curve which results in a smoother drive and an increase in power.
For the best results use with 2" HD8 carbs and 6 branch exhaust manifold but it can be used with smaller 1¾" carbs and the O.E. cast iron exhaust manifold.
2" BUT CAN BE USED WITH 1.3/4"