i buy/use all NCP napa part numbers when it comes to the ball joints. lifetime warranty and no questions asked when i return the parts with old ass receipts lol. I was told long ago they are the high grade moog parts with NAPA branding on them but dont know if it still holds true with all ive read on some of these moog stories. i know these parts have not faltered on me any worse then they did years ago. i did buy an AC Delco lower ball joint and install it. has about 10k on it and still tight but dont know if i fully trust it. i bought all AC Delco parts for my tracker steering and they didnt last 3 months but its also far from stock lol.
So far i get about 50-60k out of the upper ball joints, 20-50k out of outer tie rod ends (depends on how hard i have been on 4wd launches or using 4wd), 40k out of the inner tie rods (they are 86 ford f150 joints for my exaxt kit, no NCP part number for them...), idler arm has 80k on it with no sign of slop, pitman arm went 50k before it wore out from too much in and out play (not back and forth, had 0 there), idler arm support has 50k and just starting to show some signs of wear. i still have one original passenger side lower ball joint with 204k on it and no more than 1/16 of play. damn thing must have been made on a tuesday.
So basically i get 50k out of the steering with 37s, 600hp launches or beating on it in 4wd while towing my trailer through the sand/cinders. way better than the 10k i use to get without this steering setup. I always carry an outer tie rod as insurance as its my weakest link. hopefully ill remedy this soon by going heim steering and fixing the nasty bumpsteer in my fabtech knuckles