I may have a spare I can measure. I'll look in the morning.
Don't have an extra. Sorry. It went away with the engine, apparently.
I'm pretty sure that it is the oil pump retaining screw, contrary to what Carl says. I think the tip shape doesn't matter, It just depends on the diameter of the pin where it goes into the blind hole in the oil pump. If someone has an engine that's partially torn down they could measure to confirm.
