I've got aa 5.3L V8 as well, just want to throw out a recommendation for the
Delphi FG0053, it's an OEM replacement and as it turns out there are a few improvements to the system. Namely, the filter is no longer external and the sensor has been swapped (will require maybe 15 minutes to cut and crimp cables) - but the new Delphi works quite a bit better. Materials have been changed and it's rated to last longer than original OEM (which.. I got ~145K miles, so I'm thinking no pump replacement for at least another 150kmi).
Swapping the pump out yourself is easy as hell, PM me and I can make you a write-up/technical if you'd like. Took me ~5hrs, and I'm not a mechanic. Fun sunday project!