Just as a brief (and not entirely accurate) history.
You have the original LTS (1,2,3 etc) that had the titanium linkage at the shock and there was the rare DH version too (bendy seat tube).
then you have the later LTS 1,2,3 team ext with the adjustable linkage thing, along with the DH version (above, still bendy seat tube)).
then 97? they changed to the lts-1000, 2000 etc, this is the one with the curved (as opposed to bendy) seat tube that disappears into the down tube, the DH dual sport ones came with longer shocks like the judy XL triple and stuff.
Then of course there are the STS'...
If you look into the GT catalogues in the archive you can maybe figure it all out.