Front disc brake conversion on Demon-Now alignment is way off. Needing help!

Don't see this posted, but have the upper control-arms been removed from the car during the swap?
If not, then there's no way the camber/caster alignment can be off that much, UNLESS there are some obvious differences in the new spindles compared to the old ones.

Are the spindles both symmetrical, besides the side the calipers are mounted?
If not, any chance you got left and right spindles mixed up and the kit was designed for front mounted calipers?

With new/different steering arms, there should only be some toe-in adjustments necessary.

These are clearly a kit based on 73-76 A-body knuckles.

The camber could be off somewhat due to the different design lower ball joint. I know for a fact the toe is/will be.

Spindles are symmetrical. Have had them going both ways on my car.

I am concerned about what they did with the upper ball joint...since normally the taper would be wrong. Maybe it comes with an adapter sleeve?