Adjustable Part Throttle (APT) Screw, for power piston adjustmen
Our Part # 3630

Adjustable Part Throttle (APT) screw allows adjustment of height of primary metering rods within the primary jets. Great for fine tuning your Quadrajets cruise Air/Fuel metering.  For use in Rochester Quadrajet models with APT located in the Throtle Body.

Freeing up the APT to allow movement, allows you to raise or lower the down height of the power piston assembly.  Makining air fuel ratio adjusting easier.

Note: Use heat to loosen and remove original APT screw.