I was explaining the advantage of using the dual advance late distributor in place of the original loadomatic to an aquaintance who has a 54 Merc 256 motor.What needs to be changed in order to use the late distributor in his Y-block?Seem to recall that the 54 dist. gear and oil pump shaft are not the same as used in the 55+ Y-block.What do you do-swap the old drive gear onto the late distributor?what about the oil pump shaft?Do you need to change the oil pump to the newer style also?