4 Barrel Billet Aluminum Carburetor Main Body - 4150 Double Pumper [Black] They are designed for stock

They are designed for stock or mildly modified engines for the value-conscious buyer

This specific retainer is designed to add to the installed height by

Try using Speedmaster steel crankshaft pulleys to increase horsepower and reduce accessory drag

The Speedmaster serpentine belts are manufactured from a synthetic neoprene compound that resists heat

This is our top-of-the-line medium profile LowRise+ Series manifold

4 Barrel Billet Aluminum Carburetor Main Body - 4150 Double Pumper [Black] They are designed for stockThis Speedmaster design features tubes instead of discharge nozzles that provide a more consistent fuel flow. Want to upgrade your street carburetor to a high performance race carb but don't have the means to do a complete carb swap? If you can turn a screwdriver, you can get 25 to 50 HP from these Proform main bodies. With no air horn, choke tower, or choke control to restrict airflow, they deliver extra power easily and affordably.