POwer brake question (should be easy for y'all).

[jorgensensc]

Hey all,
I have a '68 with a front crossmember and disc brakes off of a '73- 87 truck. I pulled a power brake booster off of a '67. It is missing the lines to the proportioning valve (although after reading some info, I think it is actually just distribution block since 67-70 only had drum/drum setups, but it looks very similar to a prop valve.) I currently have manual brakes (obviously) but I have a wilwood adjustable prop valve on the rear brakes. Can I hook my lines up the same way to the power brake master cylinder, using the wilwood adjustable on the rear instead of buying a prop valve like is commonly on there? Also can I use the master cylinder off the drum/drum setup off the 68, or do I need to get a disc/drum master cylinder from a 71/72? For the 24.00 I may go down to autozone and buy a new master cylinder instead of jacking with this old crusty one. I'm also a little confused about the residual valve that has a certain pressure to the rear brake lines. Do I need that too, or is that also the function of the prop valve. Let me know what y'all think. Enlighten me please!
Shawn