Location of Numbers

• There are two sets of different numbers on Holley carburetors. These number series are found either on top of the body casting or on the right-hand side of an installed carburetor.
  
  

Top Set of Numbers

• Stamped into the body casting of the Holley carburetor is an alpha-numeric series beginning with the letter "R." Following that letter are six to eight numbers. This number is the carburetor's serial or list number. You will need this number if you buy gaskets or make adjustments to the part.
  
  

Bottom Set of Numbers

• Right below the serial number, is a second set of numbers that form part of the product's identification numbers. This four-digit number is the date code that, as the name suggests, identifies the carburetor's production date.
  
  

Use for Numbers

• Download the Carburetor Numerical Listing from the Technical Library on the manufacturer's website. Reference the numbers to obtain technical specifications for the carburetor.