Designed for small-block and small displacement big-block engines, these carbs are recommended only for stock to Performer level applications. They are not recommended for use on RPM or Torker II intake manifolds. Match with an Edelbrock Performer or Performer EPS manifold and other brands of similar design. Calibrated 2% leaner than #1405. Includes both timed and full vacuum ports for ignition advance. Comes with: Metering Jets – Primary .098, Secondary .095; Metering Rods – .075 x .047; Step-Up Spring – yellow (4 Hg). Includes exclusive 36 page Owners Manual (except part #1400). Tuning required