My truck has 256,000 miles on it and I may have to tear back into the front of the block to rectify a suspected waterpump leak. If and when I do, should I swap the oil pump?

I can do an oil pressure check, but the guage is showing good pressure at startup (cold) and low normal at idle (hot) and at highway speeds its upper limits of normal..... Thoughts? Should I swap it out or let sleeping dogs lie?

 

Oil pumps run in a constant oil bath, and run under very light/constant load. As long as your oil is clean, the wear is usually not enough to worry about at any mileage. Run dirty oil too long and it's a different story.