canadian z28

Last year i noticed my oil pressure drop towards the low side. Its sitting 1/4 of the way below the 1/2 mark. When i rev the engine up the pressure jumps up then back down. I'm assuming its the oil pump or something related to it. I was wondering how are they to change and are there any little things to watch out for. The water pump is leaking so i figure its a good time to do this.
t.i.a.

PlainwhiteZ28

Yeah your oil pump could be loosing *****, or your bearings may be wearing down. IT would be good insurance to replace it while your doing the water pump, your almost there anyways besides the crank pulley and dropping the pan. Hell might as well throw in a cam