My builder passed before I finished my build. He or someone in the shop forgot to put the eccentric counterweight back on when re-assembling the block.
 I have one on the way, but need to know if they are generic or specific to the build (i.e are they like wheel weights, used to balance the cam shaft)?
Sorry if that sounds dumb, but the engine ran like a sewing machine with out it,
except for the wrist pin type knock,
at low idle, when at temp, and it loosened the.actuator rod pivot pin, on a good pump.

John

The fuel pump eccentric is not balanced to the individual engine.Use your new one and do not worry about it.

As Steinauge points out, the fuel pump counterweights when used were all the same.  If not used, there is a keyed washer that’s used instead and that keyed washer is the same thickness at the counterweight.  If the counterweight was left off and the alternate washer/spacer was not used, then the fuel pump eccentric will sit too far to the rear but of more importance is there’s a good chance that the cam gear retaining bolt has prematurely bottomed out on the camshaft snout due to the last spacer that fits in front of the eccentric now also sitting too far back.  This will make the camshaft end play excessive.  Just take a hard look at the components as you remove them to see what you actually have.  Here’s a link to a past thread showing the location of the various parts holding the cam gear to the cam.
http://forums.y-blocksforever.com/FindPost27029.aspx

Lorena, Texas (South of Waco)

Thanks guys,
Ted, you hit it exactly, bolt was bottomed, eccentric wobbled and caused the fuel pump to shake out the actuator pin.
There is not a lot of time on the motor, just breaking it in, and a trip to the muffler shop under power, maybe 5 miles total.  What should I be looking for?  The only thing I noticed is the timing chain is tight on the right and has about a 3/16ths" play on the left, facing the motor
Is there a way to tell if it should have the washer or the counter weight, will it make a difference?

Once again thanks for helping me out with this , you guys are great
John

It doesnt matter.You just have to have one or the other to act as a spacer.

Thanks for the comments.
It seemsI have to ask for  a little more help. The member who was going to hook me up with the counter balance weight searched his stash and was unable to find one.  If anyone has one, or can tell me where to find one, I would appreciate the help.
John

You’re fine with the 3/16” deflection in the timing chain.

I don’t have any spare counterweights but I do have the keyed spacers that take their place.  If you’ll send me your address via email, I’ll send you one.  My email contact information is at www.eatonbalancing.com .  While you’re looking at the hardware that retains the cam gear, be sure the spacer that is first on the camshaft (most rearward) has the chamfer facing the rear.  The chamfer facing forward will have the camshaft end play being excessive.

The fuel pump concentric counterweights for the Y were only used on the 54, 55, and early ’56 models.  After then, the keyed spacer was the standard piece used in place of the counterweight.

Lorena, Texas (South of Waco)