KB 850 cfm Alcohol Holley Circle Track Carburetor. Condition is "Used". Holley pt no 4781 850 cfm double pumper modified by KB Carbs for Alcohol fuel and circle track racing (in this case dirt track) includes removing choke and air horn shaping of the top new special metering blocks 4 corner idle adjustments modified butterflies.and more . This carb ran fine just went to a bigger one it's been sitting and definitely needs a kit which about 60$ . KB charges 0 plus parts for a rebuild and a new KB alcohol 850 is 00. Need more info or pics let me know. Emporiumdave