Exalted by 40

[Dreadlorde]

I just rolled a new undead rogue, and instead of the skelton horse I wanted to get a raptor. I've been looking on wiki's and other forums for a couple of days now, but I can't find the one thing I'm looking for:

How many stacks of mageweave would I need to turn in to get to exalted status with the darkspear trolls?

Thanks for any help.