I have disassembled the lower unit on my 1924 A Johnson and have a question about the correct way to re-install the gearcase cover or head. When I took it apart the lube holes and flat section were facing down. There is a wear mark on the top side where it looks as if the pinion gear has been rubbing. It seems to me this is incorrect as the flat portion would give the pinion gear clearance. The book says when re-installing the gear head be sure not to get it up side down, but they don’t say how to tell. It will go on both ways. Thanks for any help!