How to tell 71-72 spindles from 73-87 spindles

[cris well]

i've bought 2 different sets of tie-rod ends for my 68 with disc brakes.

first i bought 71-72 ends and sleeves. the outers fit good but the inner wouldn't fit thru the hole in the center drag link.

then i took my old ones with me and matched them up to 68 inners and outers and sleeves.

now i've been reading up that depending on what year spindles were used, you need different outers to match the spindles along with using an outer 68 for an inner so the threads will be right again.

so i need to know if you can tell by looking at them if i have 71-2 or 73-87 spindles so i can get the right outers this time around.

the guy i got the truck from evidently used the old 68 stuff on the disc brake spindles incorrectly. i drove the truck around some and didn't notice anything out of the ordinary though.