Drop spindles and trimming control arms

[69SCSS]

Couldn't find the exact info, but i just swapped in Western drop spindles, and the upper control arm contacts the spindle at the top when the suspension is unloaded. On the bottom the spindle hits the stop early, so my turning circle will be reduced. anyone know the right amount to remove from each to fix this? Don't want to just cut and trial and error if it's been done before (I'm sure it has) and documented. I have stock '69 drum brake lower control arms.

Thanks for any help.