Looks so much more proper with the new wheel and tire setup. Have you chalked the tires to find true proper pressure. No use driving it around at 50 if it only needs 30 to wear correctly.
How much caster does it have with the long shackles and adjustment wedge? I think 5-8 is typically a good rule of thumb for straight axles. At least your wedge is in the right way. when I was a dumb ass kid I thought it was pinion angle adjustment.
What brand Balljoints?
Ive seen one out of maybe 10 Redhead Boxes we have installed at our shop have memory steer out of the box. I think they recommended a 500 mile break in, and if it persists they will give you an amount to spin the preload adjuster out to maintain your warranty.