Here's a thread with the info you need.
http://67-72chevytrucks.com/vboard/s...d.php?t=444823
You may want to contact forum member "t korinek" (first name is Tom) in Mesa. A couple years ago, I bought everything I needed for my 69 3/4 ton from him. I got a master, booster, prop valve and complete front suspension including the cross member. He'll probably be able to set you up.
Jim