Most spindles have some amount of camber in them, to obtain the correct amount of king pin inclination. This allows the tire contact patch to pivot around the axis of the king pin. Turning the spindles upside down will mess up your contact patch location and also give you a goofy camber measurement. I would look for another solution, like an early Econoline dropped I-beam axle or, as I am doing on my '30s era champ car, a '50s era Ford pickup beam axle.
