Originally Posted by klhansen
Do you have one to confirm that Jerry? My recollection is that the hex head was a 1/2", which would indicate a 5/16" thread. The jam nut is larger, I'm recalling 9/16" hex. And I do think that the tip is stepped down to match the blind hole in the oil pump.

Yes, I have several engines in various stages of disassembly. I will take a few pictures, along with thread diameter and pitch measurements in the daylight tomorrow.
Jerry

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