Clean proportioning valve HELP / SETUP

[77Blue]

Hi all,
I have a 1977 Chevy C20. I just put in a new master and new vacuum brake set up. I also threw on a GM14 bolt disc brake conversion kit from RuffStuff Specialties.
https://www.ruffstuffspecialties.com/R2262-A.html

(** If you did this kit as well and you need emergency brake cables, get these: https://www.performanceonline.com/19...ke-Conversion/ **)

The rear disc brakes are not engaging. I adjusted them 2 times. still not engaging. I want to upgrade a new proportioning valve that I can adjust. Has anyone done this on a square body?
The reason I ask. I do not want to just select a random one from Summit and throw it in. I want a decent one, but more importantly, I want a clean and easy way to install it. I do not want to cut corners, I want it to look clean. So I figured I would ask to see what others may have done on their projects.
Thanks!!