I know the answer to this question is simple; I just don't have the physical reference (at least I think I don't) to provide it. What I need to know is, what's the distance between the "top" of the kingpin/spindle boss and the "bottom" of the axle on a stock '47-up I-beam? I have an aftermarket dropped axle, and what appears to be a dropped-stock axle. The latter seems to be more dropped than the aftermarket one, and when looking at the axle on my pickup, it appears to be the same drop as the supposed dropped one. So, either I have two stock (non-dropped) axles and one dropped aftermarket axle that isn't really dropped, or three dropped axles and no stock ones!
