OK, based on this post, I feel comfortable using my radius arms from my 67' for my disc brake converision. I'll use the 75' Ibeams, kingpins, and spindles:
http://www.fordification.com/forum/view ... hp?t=29929
However, my other question is...
If I change out the pitman arm on my 67' with the one I have for my saginaw box, can I use my 67' tie rod and drag link instead of the one from the 75'?
Edit: I found this picture and notation in one of the tutorials:

"Here's a view of the differences between the stock '67-'72 vs. '73-'79 tie rod ends, where they connect to the spindle's steering arm. This is due to the later spindle's steering arm being thicker. Therefore, early steering linkage cannot be used with later disc-brake spindles without some grinding on the spindle's steering arm to allow the tie rod end to protrude through enough to install the castle nut and cotter pin."
Has anyone tried this? I'm trying to avoid buying a new drag link. I don't think the one of the 75' is repairable.