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I am going to replace my fuel pump with a Holley high performance pump. I have never replaced a mechanical fuel pump before and would appreciate any advice/steps/best practices you might be able to share with me. I almost have this beast ready for road duty but little things keep popping up!

Thanks for your help.

All the best,
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...Turn the Engine over by hand to make sure the Excentric is at the 'Low' side Heel! Then Your not fighting the spring in the Pump to get it into position. The 351 Cleveland mounts the pump with One Bolt and One stud with a Nut. Install the Gasket First!
The stud is on the Bottom so You can hang the pump up on it then install the nut;(The mounting hole for the Stud is SLOTTED so You can put the Nut on first and then 'Hook' the Pump onto it)Loosely. Screw in the Bolt. You may want to put washers under the bolt and nut. Tighten Both up evenly!

NOW! My advice is to carry a spare electric pump ready to wire-in tempararily, just to get You Home!! Because the Holley Mech. Pump uses 'Pressed-in' Check Valves! One of them 'popped-out' inside My Holley Pump and left Me stranded until the Transport arrived! I've been useing the Electric ever since. I took the Holley apart and found what I described. When I get around to putting it back together; I will be sure to 'Lock-Tight' that check valve, when I press it back into it's Counterbore!!
Otherwise They are a Great, Beefy Pump!
Use a Fuel Filter on The PRESSURE Side. And use the Steel Can Style!! NOT a Plastic or those Glass see-through pieces of Crap! Try to place the Filter as far away from ALL heat sources as Possible. You've been warned!

Good-Luck with It!
Last edited by marlinjack
I'm with the rest of the guys. I had a Holley mechanical pump that didn't last 3000 miles. Broke internally. Left me stranded at the side of a busy highway with fencing on both sides. Thank god for cell phones! Google around a bit and you will see that these pumps are a shameful piece of $#!+. Don't buy one.

Later, Mooso.
I am going to show my ignorance here with a series of questions:

1.)What is the best way to turn the engine over by hand?
2.)What is the "excentric?"
3.) How can I tell if the Excentric is at the lowside heel?
4.) How do I know if I have the pump in position correctly?
5.) Should I use any gasket sealer? Any suggestions?

Thank you!
1. Use a Breaker Bar with an extension and Socket at the Damper Bolt. Turn the engine over Clockwise!! So as NOT to Loosen the Bolt!
2. The 'Excentric' is a stamped steel 'Cam' the rides on the face of the Camshaft Sproket, at the front of the Camshaft. It actuates the Fuel Pump ARM!
3. By 'Trial and Error' when inserting the Pump into position. Unless you can see in 'there' with a Flashlite and a 'Inspection Mirror'.
4. There is Only ONE Correct way It can be Installed!
5. I recommend using the proper 'Paper/Cardboard' Gasket with a sealer on both sides (such as Permetex or an RTV). After cleaning all contact surfaces with Lacquer Thinner! Very Oily down there for JUST a Sealer!
6. With whatever Pump You go with; it is always recommended that a 'Moly-Lube' be put onto the Arm Contact Surface of Any NEW pump to aid in Breaking-In!
Last edited by marlinjack
FWIW, there are two different fuel pump eccentrics: the early one is concentric two-piece stamped steel while the later one is a one-piece hardened steel unit. The type of eccentric you have dictates the double-row cam chain you'll need if you decide to change things around. I read the stroke generated at the pump by the two eccentrics may be slightly different too, but haven't verified this.
I recieved my new Robb MC 351 Fuel Pump but didn't realize it didn't include fittings. I have a stock fuel line set up (rubber coming from the tank and a partial metal line from pump to carb that links to a rubber line that connects to a split metal line to each carb bowl). I emailed the supplier asking if he had fittings that would allow me to fit this to my stock system. He replied:

"Sorry but we don't have fittings to connect to stock lines. The ports are 1/2" pipe (NPT). A hardware/autoparts store should be able to help."

I went to the parts store and I got a blank guy suggested I use air tool fittings. I could see how those fittings would work from the rubber line from the tank to the pump but I am not sure how I would reconnect the metal line from the pump to the carb? Any thoughts?
Thank You,

I had tried to install one of the Robb Mc pumps and was not able to do it with the engine in the car at that time. After installing a new engine with the pump installed I had no problem. I think that if you drained the system and removed the hose it would be much easier. Putting the hose back on is not bad. I know what you are going through.

Regarding the fittings you can get them at a hardware store. What you need is a reducer from 1/2" pipe to 3/8" pipe and go from there.

Mark 5481 & 5461
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