Here are some useful information on Racial mounts for reputation, hope it could help you. If you have no time to earn the most secure World of Warcraft Gold, you can buy it from our website at the lowest price. We will try our best to help you.
Edit: Update. It can be done just through questing.
You could go back to the Undercity and found some quests there that did give some spillover. You find many did not give spillover but many did. You also found some quests wow gold over there that sent you back to Orgrimmar to do some quests and without going over to the under city you never get those Orgrimmar quests.
Bottom line is, after running 'everywhere' and double checking places you had already checked, you could get Dark Spear Troll Exalted. All total you have just over 900 quests done.
It is possible but it takes a lot of questing, doing every single quest you could find everywhere, because some quests chains that start off not providing the reputation for the Dark Spear Troll, which may have a part of the chain that ends up providing some Dark Spear Troll repuation.