I am thinking about replacing the 7.5" rear in my monte ss with a (possible) Quick Performance 9" rear and thought if im going to spend that kind of money why not do the extra (the first time) and upgrade to disk brakes. How ever I dont know what to do about the proportion valve since really it is there for the whole disc n drum brake combo set-up. The suggestion was brought up about using a brake bias valve (aka wilwood). A little insight would be appreciated am I goin in the right direction?