Rochester 4BBL Quadzilla Quadrajet 840-900CFM Stage 4





  • Surface baseplate for flatness and glassbead for bright silver finish.
  • Choke pull-off modified for faster secondary air valve response.
  • All vacuum ports plugged
  • All idle and off-idle functions modified for long duration, low vacuum camshafts.
  • All fuel circuits, air bleeds, and calibration components engineered to match specifications of YOUR engine to provide maximum possible HP&TQ; as well as response and consistency.
  • All choke hardware removed and openings plugged
  • 750 to 900 CFM available.
  • 1 YR warranty all parts and labor
  • .150″ Needle and seat assembly installed for maximum fuel delivery.
  • Drill idle air bypass holes in primary throttle blades to maintain proper throttle blade angle at idle, ensuring proper function of idle and off-idle circuits.
  • High capacity accelerator pump featuring materials that are resistant to alcohol and other additive commonly found in today’s fuel
  • Install bushings in baseplate to eliminate any potential vacuum leaks at primary throttle shaft.
  • Primary airflow is increased by 90 CFM!
  • Strip to bare metal, inspect for defects, then apply dichromate coating for brilliant gold finish.
  • Strip and cadmium plate all hardware, including throttle shafts, linkage, levers, spring and screws.
  • Select only the highest flowing castings
  • Select highest quality cores for best performance and reliability
  • Secondary metering rods and hanger selected and high speed air bleeds resized for maxium full throttle horsepower and torque.
  • Secondary fuel pull-over circuit modified to eliminate any potential sags, hesitations during initial secondary opening. This circuit acts as the “accelerator pump” for the secondaries and is critical to off-the-corner or starting line performance.
  • Primary and secondary main wells resized and balanced for increased fuel flow capacity at high RPM.
  • Secondary Booster venturi ring removed from primary by extensive hand modification.

Additional information

Weight 15 lbs
Dimensions 15 × 15 × 15 in


There are no reviews yet.

Be the first to review “Rochester 4BBL Quadzilla Quadrajet 840-900CFM Stage 4”