I am installing Mustang II upper control arms from SPC. These do require reaming of steering knuckle. Upper taper is simply made to be an exact same size as the OE lower ball joint taper using your choice of 7 degree ball joint reamer. This setup is easily rebuildable and allows fine tuning for caster and camber.
SPC arms come with ball joints that are way too large, so 2x 97001 ball joints are needed.
Also, SPC arms use 5/8 ID bushings. SPC sells spacer adapters for bushings which are p/n 944505. 4 of them are needed.
Finally inner part of arm will hit frame if steel spacers between arm and frame are not used. I plan to use McMaster Carr 1/2"ID x 1"OD x 1"W spacers for forward part of arm and 1/2"ID x 1"OD x 1/2"W spacers for rear mount of arm to frame. Using 1/2"-20 x 12" bolts from McMaster to secure.
SPC Arms- 97260
Ball joints- 97001
Bushing spacers- 944505
These fit the stock 14” wheels. Will post pics once fully installed.