[silverstreak]

Different brands of tie rods can have different lengths of threads, to a certain extent. I would measure from grease fitting to grease fitting between the inner and outer tie rods to get a closer measurement. If you knew it was a new old stock GM replacement then you might be able to get away with counting the number of turns.
The best method is to measure the toe in with a 2 x 4 prior to removing the old one, then adjust the new to the same spec so you won't wear the tires on the way to the alignment shop.

Also, I would back the nut off the tie rod end, almost all the way, where it goes into the steering knuckle and use a pickle fork or pry down on the tie rod with a crow bar while hitting the side of the steering knuckle where the rod end seats.