Magnum motor with Mechanical fuel pump ?

MOPAROFFICIAL said

I've had this scenario with a 340. I was thinking the chain set was the culprit. JP performance billet. I put a tensioner on it and that stopped. I noticed it had some slop with little mileage..chain slack was my final conclusion...but could have been the arm on the pump too.

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Mine had some witness marks and went away after I banged on it with a hammer. The cam moving around is purely my speculation though. For all I know, the slop in the bolt holes of the pump were enough to make it clear. That pump arm was hard and I'm not certain I bent it at all. The noise stopped so I didn't care. :D