I currently have about 350k miles on my made in China, Cummins lift pump. Typically they have lasted about 300k so I'm thinking about replacing it as preventative maintenance. Before you remove the old one I recommend you purchase a new 90 degree hose from the prefilter and a square cut gasket parts #3923194 for the line that connects to the top of the prefilter. Personally, I wouldn't touch the one you have.
I've replaced the 90 degree hose from the prefilter to the lift pump. Where can you get a square cut gasket #3923194? When you said (Personally, I wouldn't touch the one you have) do you mean the one that is in the truck(original)? or the one on Ebay? Thanks Dave