If you can reduce the vibration affecting the carburetor, it will improve the fuel curve and increase horsepower.
There have been several attempts in the past to dampen these vibrations. These Second Hand Pros Carburetor
Vibration Isolators are the most effective and user-friendly parts available. Our unique design relies on a 1/4”
thick aluminum plate, which is encapsulated within the special durometer rubber base, positively isolating the
carburetor from the manifold. Overall isolator thickness is 1".The aluminum retainer ring can be bolted directly to the manifold as tightly as needed, and the carburetor can be bolted to the internal plate with the proper amount of torque, and the harmonics from the manifold will still be separated from the carburetor. They are most beneficial on sheet metal intake
manifolds. The tapered throttle bores, and annular “shear” rings are molded right in to the rubber. They function
to not only increase flow, but are extremely effective in stopping reversion. If your sheet-metal manifold has a flat lid you can drill and tap eight 10-24 holes in your lid to bolt the vibration isolators directly to your manifold. If you want to use the stock Holley® pattern in your manifold we offer P/N CVI 4A 1/4” thick aluminum adapter which bolts directly to the manifold, and will then accept the vibration isolator.
The 4150 has tapered bores transitioning to a “Torpedo” that hangs down in the middle and directs flow. Thanks to Bill "Grumpy" Jenkins for assisting with this design. They have a small footprint and even fit on V-6 manifolds.