Drum to Disc on Early A Body Problem

I have mine on the rear of my 66 Valiant w/Cordoba rotors with zero issues.

on another note do I see a washer under the lower control arm on the lower ball joint?
could that be causing the issue?

also the caliper can be mounted front or rear as long as the correct hoses are used.
I unfortunately don't remember the part numbers or applications for the hoses.