67 C30 front brake drum to disc questions

[Elephanthead]

OK, I have read every post I could find and this is my plan, please correct me where I am wrong on any point.

1. If I want discs in the back, I need to swap axles, I am saving this project for another day. The rear will stay stock dually drums.

2. My plan is to swap the spindles in the front for 88 or later spindles off of a C3500 8 lug whatever junkyard donor.

This is where I need help, the tie rod issues I have found answers to, but I need to know if the ball joint for an 88 C3500 will bolt into the 67 a arms, or not. I see in the easy disc conversion thread that the lower one should bolt in, but it doesn't specifically address the upper for a C30, only a C10.

Also, I will grab the proportioning valve and calipers and lines off of the donor or similar donor, I would like to stay with manual brakes, what are my options for a master cylinder?

Thanks for any help or advice, if I am crazy or wrong please let me know before I start junkyard diving.