1969-72 Chevelle Water Pump, Long Style, Big Block,

  Note: Spacer maybe required for upper alternator bracket to fit correctly.   The Short and Long of Chevy Water Pumps Chevy Camaro mechanical short style water pumps measure 5-5/8” high from the shaft down with the pilot shaft diameter measuring 5/8". Long style Chevy Camaro water pumps measure 7” high from the shaft down, and the pilot shaft diameter was 5/8" as well. Do not mix and match pulleys from short and long water pump engines because this will cause pulley misalignment. An easy way to find out what style you have while your pump is still installed on the motor is to try to stick your hand between the water pump and timing chain cover. If you can slip your fingers in-between you have a long, if not you have a short. div>