Stage 3 Holley 2BBL Modifications – 2003


Stage 3 Holley 2BBL Modifications

Category: SKU: 2003



Stage 1 Modifications

  • Machine body surfaces for maximum gasket seal
  • Install Anti Pullover System (APS) to eliminate fuel siphoning from accelerator pump nozzle at high RPM
  • Position boosters precisely in center of venturi for best flow and equal signal
  • Balance all metering passages, then resize and modify for optimum fuel curve, including:
  • Emulsion, High Speed Air Bleed, Idle, Idle Air Bleed, Main Well, Main Well Exit, Power Valve, Transition
  • Install hi-flow .130″ needle and seat for consistent fuel delivery and float bowl volume
  • Remove and block all vacuum ports and choke hardware
  • Assembled with reusable gaskets for ease in tuning and service
  • 1 YR warranty all parts and labor

Stage 2 Modifications

  • Will pass gauge test if carburetor is not removed from intake manifold
  • Machine baseplate throttle bore to 1-3/4″ an increase of .0625″ over stock.
  • Blend lower venturi to match larger throttle bore. Upper venturi remains stock to pass gauge test.
  • Increases maximum airflow and promotes better fuel distribution to end cylinders
  • Choke tower is removed with Bridgeport vertical milling machine to increase air flow, and balance air flow of primary and secondary venturis. This promotes increased high rpm horsepower. This is a no cost option however an optional electric choke can be
  • Throttle shaft thinned to reduce area and increase peak airflow capacity, stainless button head screws used to secure throttle blades

Stage 3 Modifications

  • Resulting Airflow = 620CFM
  • This carburetor is intended for classes which have no restrictions on carburetor modifications, and it will “NOT” pass any type of gauge test
  • Upper venturi enlarged to maximum possible size to create dramatic increase in peak airflow capacity
  • Removable air bleeds installed in main body
  • Booster venturi modified for increased airflow as well as better signal strength and atomization
  • Removeable air bleeds are available on all stages when rules allow


Additional information

Weight 10 lbs
Dimensions 13 × 13 × 13 in