I'm wondering what the distance is from the Lower balljoint mount on the mustang II spindle, to the hub face on a mustang II spindle, with disk brakes.
Ike, great question. A couple of factors make this up. If you are using Wilwood spindles and hubs, there are detail drawings on Wilwood's website for several different spindles (standard height and 2" lowered) and many hub options. If you will be using disk rotors with hats, then hat thickness adds in. With the bolt-on style rotors, there is no added hat thickness. If you are looking to base the distance on the lower ball joint pivot point instead of the mounting point, then ball joint length and king pin inclination come into play. Howe Racing has a number of ball joint lengths available for their Moog K727 compatable BJs. Then there is the seating of the BJ into the spindle's taper to consider...
If you can't get the detail info on the parts you are going to use, you may want to consider buying what you intend to use, assembling the spindle/hub/BJs and measuring them. Different combos, different results. And for the Mustang II spindles, a lot of combinations are possible.