I recently purchased a SSBC rear disk conversion kit #A125-1 & was wondering, do I need to change my current disc/drum prop valve for a disc/disc prop valve? No info in the install manual says I need to but my thinking is that I do. Any help or guidance? Gonna call the "tech support" line but any other info would be appreciated. BTW its a 67 327 4spd coupe w/power brakes. thx. Mike