Chris,   I'm putting the oil pump in my 77 engine, and tried to follow the service manual instructions to orient the slot visible through the distributor mount hole.  I have the marks on the crank gear and timing gear lined up.  I'm noting the off-center slot in the top of the oil pump shaft and orienting as directed.  But, the slot is 10-15 degrees from being horizontal (parallel to the block) .  If I pull out the pump and move the gear 1 tooth, it's 10-15 degrees off horizontal in the other direction.

If I have that off-center slot rotated 180 degrees, so that it is away from the block rather than toward it, I can make it parallel to the block.  But I know that is not correct.

Perhaps I can adjust the distributor alignment to correct for the problem, but since it is not working out as shown I wanted to ask you about it.

Thanks very much.

Tom