needs to be between 1 and 3 degrees, if you drew a straight line between the tran tail shaft and the rear end pinion, if your rear end was 3 degrees up you trans should be between between 0 and 6 degrees down, it has to have some angle or the u-joints will wear out to quick, found this out the hard way, set a 33 coupe up with the angles the same, u-joints didnt last any time.