I have a 67 A body barracuda. Its a 340 car w/ 8 3/4 rear. currently it has front disc ,I'm putting rear wheel disc on it. I spoke to a Mancini tec. and he informed me that I don't need a proportioning valve that I could just run the master cylinder with a block valve..question is have you ever heard that before....I don't want to hit the brakes and end up in the ditch some where...not cool any advise will be great . btw I have a m/c with the 15/16 bore non power . long live the Mopar