Xterrian,
I've got an old mechanical clinometer/altimeter pod from an older 4Runner that you might be able to hook up some electronical doo-dads to to take a reading from somehow. Hell, you can even see the internals of it here:
http://4crawler.cruiserpages.com/4x4/CheapTricks/index.shtml Click on the Clinometer Tweaks link.
You want it, I'll send it to ya, no charge.
Brent