I posted a similar thread in the 60 section, Hope it's not too cross posty...Got an 86 booster/master/prop valve to put in my 77 piglet. The swap is plain and simple enough-BUT....I can't find any info on the prop valve dealio and how to use it w/ the pig. It has 4 ports on it, and a big F and an R embossed on the casting of the body. MY GUESS(which is not good to do w/ brakes-so I ask you all) is that the front and rear circuits are both to be plumbed thru the PV. Is this so? IF so, then which ports on the PV correspond to which ports on the MC and basically.....How do I hook up my front and rear lines??? Thanks all