This manifold is a great manifold for big block Chevys. It’s capable of supporting 600-700HP and has a 3000-7500 RPM range. This is a very affordable manifold that makes outstanding power and torque. This manifold is available with an oval port or rectangle port. For the rectangle port, you can get it in a 4150 flange or 4500 Dominator flange. All manifolds are available in satin or chrome polish.