The difference in horizontal separation between the old and new axles was well under an inch. However, the vertical separation between the two varied by 11⁄2 inches. You want the upper and lower control arms to be as close to parallel as possible to minimize caster and pinion angle change as the suspension cycles. We were worried about the 11⁄2-inch change, but Wade tells us that having the control arms further apart at the axle is more desirable than control arms that are further apart at the frame. If they are further apart at the frame there is more likely to be unwanted caster and pinion-angle changes as the suspension cycles.