It should help, since the oil pump will also wear as the engine does. When the pump is removed, also change the rod that drives the pump from the distributor. It's a relatively "small" investment. If not, make sure the "ears" are not starting to twist.
There are a lot of places on the motor that can lead to low oil pressure. You are not solving the problem with a new pump, but you will be putting more oil through it, which will help for the short term. Also go to a heavier oil, like SAE40 or SAE50. Anything you can do to keep the pressure up will help.
