Hmmmm, grown men “comparing shaft lengths” sounds a bit strange 

As long as the pump turns without binding and the shaft can't come out with the distributor, the motor does not care which one you use.

So having a too short intermediate shaft will have no consequence(s)?

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... grown men “comparing shaft lengths” sounds a bit strange    

In this day and age? Nothing would surprise me anymore.

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Florida_Phil seems to have the best scenario. The mid section (ARP shaft) is too large to pass through the pilot hole in the distributor gear thrust pad so no star washer needed. By being a bit too long he trimmed the pump end to make it fit with out binding. This should also insure full engagement into the distributor and the pump.


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I assume most people on this forum possess at least some mechanical ability.  If the shaft is too short and falls out of the oil pump, you are screwed, 

By being a bit too long he trimmed the pump end to make it fit with out binding. This should also insure full engagement into the distributor and the pump.

Well (and I am trying not to be aggravating), if the shaft is not the correct length for whiscruber ... ...

EDIT -

... whiscruber ...

... which ever ...

pump is being used, if too short, the DIST end is tapered for easy DIST install, and may not engage the DIST ROTOR SHAFT fully and begin to booger both the pump shaft and/or the DIST ROTOR SHAFT. If too long and the DIST is force installed, you will have binding in both the DIST and PUMP.

And who knows what specs AARP, MELLINGS or any other vendor used according to which style pump or shaft usage?

Please don't hate me ...

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No hate here, just great we can share all this information for the benefit of all. You picked up on the possibility of a too short intermediate shaft and expanded on it. But if it will make you feel better, I may hold you to your offer from a couple years ago for that beer.


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After visually checking the block housing, there is a step in the oil pump shaft hole like Ted said that stops a correct size 5/8" star washer.  The picture of the star washer makes it look as if the washer goes on the outside of the housing, not inside.  That is what started my questioning the answer.  As for the ARP shafts, the smaller star washer on  the earlier shafts was 1/2", and they would actually pull through the hole where the distributor shaft rests at the distributor end.  If you are having trouble wondering if the shaft is too long, or too short, you can easily move it up and down by hand with the oil pump and distributor installed to check for free play movement/engagement.  There are many ways to inspect for proper engagement if you take the time and think it through.  I found that a small grade 8 washer with a 5/8"od will sit on top of the 1/2" star washer and keep the shaft from coming out when the distributor is removed on my 375 Y back in 2017.  I searched the internet for the 5/8" star washers, and came up with zero available.  There are all manner of 9/16" and smaller, but no 5/8" I could find.  So save any you find when taking apart a rebuilder for future use.  Joe-JDC

JDC

      [/quote]

There was also a problem with some blocks especially when using the ARP HD shafts or Precision Oil Pumps Ford Billet HD driveshaft from slag material left behind when the block was machined at the factory. The drill did not completely pass through top to bottom  the machined hole above the oil pump. There was a ring of casting material left un-machined that interfered with installation. Most time rubbing on one side of the HD shafts. Ford even put out a TSB to correct the problem by drilling through this slag material for the early shafts. I would have to check my TSB's for article number. .

Very good information as to how the star washer is designed to work at the oil pump end, makes sense. I realize this thread was to question the position of the star washer when after a few posts the ARP shaft was brought in to the fold and that's what I was, and still am trying to clarify. I don't know if the standard stock hex drive shaft is still available or is the ARP the only game in town now? Would be interesting to know if the ARP, with it's larger mid section, is what eliminates the possibility of being pulled up and out through the .454"aprox. pilot hole at the TOP end?   Providing the shaft is the correct length, then this would eliminate the need for the star washer, IMHO. Knowing the mid diameter of the ARP should answer this. Thanks, JEFF..............


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