Chrysler Mopar BB 413 426 440 HiRise Aluminum Intake Manifold [Black] The main difference is that

The main difference is that there is an open area under the plenum chamber

this stand blends seamlessly into your life

The cells have foam in the base to prevent fuel aeration

dual plane fuel injection intake manifolds allow the installation of dual throttle bodies on late model LS Series engines

and excessive emissions

Chrysler Mopar BB 413 426 440 HiRise Aluminum Intake Manifold [Black] The main difference is thatStep up to the high rpm power of an open plenum with Speedmaster HiRise intake manifolds. These cast aluminum manifolds accept square bore carburetors and are pressure tested to ensure maximum performance. They start to make awesome power around 3,000 rpm.