Gonna necro this old thread for some clarification and to keep the info in one place.

I need to replace a busted rear lug stud and found RockAuto lists 4 different lug studs for my '87, but no application notes (front vs. rear wheels, or RWD vs. 4WD), apparently in 2 slightly different styles along with some puzzling differences in dimensions:

Short 7mm shoulder:
PTC 97188 - Thread length 37.5mm
DORMAN 610262 - Thread length 27.8mm

Long 12.5mm shoulder:
PTC 97232 - Thread length 44.5mm *
DORMAN 610312 - Thread length 28.266mm
(*I think this spec may be in error, as it's greater than the spec'd Overall Length 42.25mm!)

Based on the prior posts in this thread, I'd infer the short shoulder is for rear drums, and the long shoulder is for front discs. Anything else to bear in mind or explain re: the differing thread lengths?