Going with a spring behind axle set up. The spring perch will be welded to the batwing. Just trying to clarify where to weld the perch on the batwing. Have read the shackle should be at 45º angle. Can this be determined while there is no load? I can get the 45º angle no problem, with no load but if it needs the load before welding, how would you go about it since it seems to me the only axle attachment points are the welds at the batwings themselves. Is this making any sense? Also, do the batwings need to be 90º to the axle or can they be angled in a bit?