My WW2.0 rod ends are 7/16" bore, 7/16"-20 right hand thread. I don't know how the price compares to NAPA but Applied.com has a huge variety of female rod ends and prices vary depending on the grade, ball material, housing material, manufacturer, etc. I replaced most of mine with rod ends that have grease fittings. But on one side of the gantry I used rod ends with oil impregnated bronze inserts. That was 18 months ago and I am watching to see which type last the longest. My own preference is for Heim brand. I paid $13.81 each for the Heim ends.