Weld in plate to get the max caster and bring strength back to the shock tower.
The reason for the needed caster mod, is the mustang spindles have an offset bearing, and were designed for 8 degrees of caster in general.
Proper wheel placement in a Datsun s30 requires the offset balljoint and shock top. David in the dark blue car just cut his front fenders instead, and kept his ball joint in the normal location.