How level the tranny is in relation to the vehicle is irrelevant, assuming the position of the tranny isn't modified and the vehicle is not pitched fore or aft a la body lift or the like(if it is, make adjustments accordingly). The engineers designed it as a package and placed the fill hole where it needed to be. Make sure the ground you check it on is level. Clear as mud now, right? <img src="/forums/images/graemlins/smile.gif" alt="" />

Fasteddy's advice is occasionally sound...