While we are in the lessons learned mode... That axle in my pictures broke... again... lesson don't weld around a tube.... My ME buddy said I just moved the load path and actually concentrated the load with the doubler., promoting a failure.
So I built a new axle, 4130 this time, 1/4 wall, no welding between the kingpin holders, it is clamped to the suspension.
John, update your profile... you are my neighbor now... you and Toto...
Scrub Radius.... Ours has always been 0, because we built it to hide the kingpin from the air. So I don't know. How about it smart guys?