[68bird400HO]

Not to keep beating a dead pump, but, I found something interesting that I should share with anyone needing one of these. I noticed that just after 100 miles or so, the cam contact point on the top of the arm looked excessively worn. Comparing this Chinesium pump to an original Delco big can I have sitting here, the arms have different shapes as they come out of the pump. The problem with the newer pumps with this arm shape appear to be that the arm goes higher by 1/4" at the cam contact point. This probably maxes out the travel of that arm and causes them to break.

Note that the RobbMc pump looks to have the original Delco style arm, as does this old Holley I have here. Not sure where or when this new arm design came into play.

See pics below.