brake upgrade -control arms

[simenad]

Looking at converting my 69 C10 power front drum brakes to 12+ disks and was looking at tubular control arms too. I know that I can use 87 disks by changing to the 87 spindles by changing to the bigger ball joints but I also noticed all the parts lists have different part numbers for 70-72 upper control arms and the 73-87 arms. Seen a youtube video where the guy disects the complete IFS and he notes the upper control arms are slightly longer. I imagine it is to improve the negative caster but was wondering if I can use the 73-87 arms/kits for my 69. From what I read the truck could use improved caster?