I bought a front disc brake conversion kit for my 69 from classic performance and am just sitting here staring at the master cylinder right now and there is a what im assuming as the proportioning valve attached to it......... originally the all drum brakes just had a metering valve on the frame which i trashed so now with the prop valve i can only see 2 holes for brake lines?? a bigger hole in the back for what im assuming is the rear brake line and another hole on the front bottom but shouldnt there be 2 holes for each side of the front disc brakes or is that metering valve needed to split up the front brake lines from the mc? thanks for your help