not so fast. the centerline of front wheels moves down relative to van as
weight is removed and shifted to frame.

dlk

>Forget the degrees, for this purpose they will only cause an inaccuracy.
>Here is simple:
>
>The wheelbase of a van is close enough to call it 8 feet.  The front
>crossmember is more or less on the vertical centerline of the front
wheels.  The front
>crossmember has to come up about 1 1/2 feet.  When jacking up the front,
the
>van pivots about the rear axle.  So . . . the horizontal centerline of the
>front wheel has to be at an elevation 1 1/2 feet higher than that of the
rear
>wheel.  Or, the van has to be on a 3 in 16 gradient.
>
>George