The Stovebolt Site Forums The Shop Area Engine Shop Putting new oil pump in the 46, Need wisdom.

I wouldn't bet on the cause of your lower pressure being the pump. I would suspect other causes such as the main bearings or cam bearings. However, if you are changing it, it is pretty straight forard. The shaft is held in by a bolt with a jam nut, up inside the side of the block. It might be a good time to adjust the shims on all the bearings and if you have a rear main leak, replace it too.