bigbeej,
That pack is much taller than a typical 2s 5000mah pack. 27mm versus 22mm, it should not be much of an issue though; like already said you will just need to extend your battery mount. That's easily done, buy the associated factory team thumb screws, and run a long screw all the way through them; or buy a longer set screw.
That pack is 3 oz less in weight than a typical nimh pack, so the truck should handle about the same but it might raise your center of gravity a little being it's putting some of the weight up high.