Designed and calibrated for small cubic-inch engines such as 305 c.i.d and smaller Chevrolet; 302 c.i.d. and smaller Ford and dual-quad applications such as Edelbrock C-26, F-28 and Street Tunnel Ram. Match with an Edelbrock Performer or Performer EPS manifold or other brands of similar design. Includes both timed and full vacuum ports for ignition advance. carburetors come with: Metering Jets - Primary .086, Secondary .095; Metering Rods - .065 x .052; Step-Up Spring - orange (5" Hg). Use carb Studs #8008 or #8024 if needed.