<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: John Brown</div><div class="ubbcode-body">Red Holley fuel pumps came before the blue ones. As I recall, when Holley recognized there was a problem with some of the red ones locking up due to insufficient clearances (end play) caused by heat generated inside the motor part of the pumps, they started painting the "new and improved" ones blue so it would be easy to tell which was which. The color change was somewhere after 1971/1972. </div></div>
As Hemicolt pointed out the red and blue pumps dealt with their performance capabilities ...as matter of fact most of the early ads just hyped the blue pump. The blue WAS NOT the new and improved and they came out the same time.
The red, original # P-6145AAA (later #12-801) was the street version and the pressure was preset at the factory-I'm thinking 5.5lbs?? and was not adjustable. The blue, original part # P-6230AAA(later # 12-802) was the competition version. It was pre set but at a higher pressure 7-7.5lbs?? and it came with a regulator and the pressure was adjustable.
Not sure when the black pump came out probably 1990''s??
Hemicolt, the rubber in the older pumps might be affected by the new gas. I would hope Holley has made new rubber gaskets and diaphrams to work with the old pumps because they are basically the same internaly.
Here are two NOS pumps. Red one is in the very early 70's box art and the blue pump is in the later 70's style box. Both pumps are identical outside other than the color and the decal on both is the same. Early pumps had different screws and the cast in Holley logo in the aluminum housing is different than today's versions and some other minor housing differences.
These pumps were introduced in mid 1971.
