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Fuel Pump Push Rod Orientation 454 Big Block

stuffs2936

By stuffs2936
in Ask A GM Technician

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stuffs2936 Enthusiast

stuffs2936

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Replacing the fuel pump on my 74 454 Cheyenne pickup, I removed the fuel pump rod to place grease on it in order to help hold it up for fuel pump installation.  Thinking it was symetrical I lost track of how I removed it. I noticed one of end of the rod had a small dimple the size of a pencil lead and the other solid. The dimple end looked like very bright metal almost chrome looking.  I guessed that the dimple would face the fuel pump actuator but now I am second guessing that decision and can find no documentation to verify it. After installation the truck is running fine, but should I be concerned? Did I get it right and if I got it backwards should I remove the pump and turn it over?  I have had this truck since 1978 and to my knowledge the rod has never been replaced.

Many thanks in advance.

Jsdirt Senior Enthusiast

Jsdirt

Posted
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I don't recall the pushrod ever having a dimple on one end. Probably due to wear, most likely. If it isn't making noise and is pumping fuel, I wouldn't worry too much about it.

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txab Senior Enthusiast

txab

Posted
Posted

Never seen a dimple either. The end that rides against the cam would the the smoothest, imo. I think the BB has the same feature as the SB engine. There is a bolt to remove on the front of the engine. You can either temp. install a longer bolt, holding the rod in position during swap or use something inserted in hole and held by hand pressure.

  • Like 2
stuffs2936 Enthusiast

stuffs2936

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Posted (edited)

Thank you both for your replies. I think my description as a dimple was misleading, I apologize .  The surface in question was perfectly flat with a small hole in the center. The hole was not deep maybe 1/32 and maybe a little over 1/16" in diameter. My understanding as been that both ends of the push rod would be hardened. Checking with a local machine shop, they had never seen this either and did not think it would matter which way the rod was inserted.  Apparently the  cam makes contact with only half of the rod in order to spin the rod to even out wear.   

Edited by stuffs2936
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