Is it just a thread at the end that is keeping it from getti started or is the whole length messed up? Or threads closer to the mating surface
If it was just the first thread on the end I would rethread if you want, but anything that is where the nut will actually have tension on it when tightened up I would replace
Granted you could probably drive a truck with just two studs for a very long time, being how thick the studs are on these trucks, it's one of those things where if there's doubt, throw it out. Kinda like brake lines and such.
Replacing a stud is a 30-40 min job at most.
1967 Series IIa 109 5 Door - Work in progress
'98 Toyota Land Cruiser 100 Series