Tech Tip: Make Easy Work of Installing a Mechanical Fuel Pump

Mark Brazelton


Here's a time saving tip for anyone that has ever spent hours trying to install a new mechanical fuel pump on a 1st generation small block Chevy. Try as you might to hold the fuel pump push rod in the up position with your finger, grease, hacksaw blade, or whatever, it inevitably slides down just as you try to insert the pump arm into the engine block opening.  The process is repeated again and again generating colorful language and/or perhaps a broken windshield!

click on any picture to enlarge

Here's the easy method. The upper passenger side motor mount boss for the old 1955 engine mount is open to the crankcase, and in direct alignment with the fuel pump push rod. Remove the factory 3/8-16 x ¾ bolt and set it aside for reinstallation after the pump is changed. Obtain a 3/8-16 bolt that is 1.5 long. Clean the threads until they look like new, or run the bolt through a die. It's important the threads are clean so they will easily turn in the block with nothing more than finger pressure.


With the push rod pushed all the way in, run the bolt into the hole until it bottoms out on the push rod. Run it up tight with finger pressure. Avoid using a wrench or over tightening as this may ding or score the push rod.
That's all there is too it. Now you can go about removing and installing the pump with absolutely no interference from the push rod. It just stays in place.  Once the new pump is mounted simply remove the long bolt and reinstall the original.
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