Proportioning Valve Question

[PunkRock247]

Hello,

I am in the middle of switching my 69 from front drum brakes to front disc brakes. I purchased a new front disc proportioning valve. My question is that there is a difference in the number of lines leaving the proportioning valve. As you can see in my picture there are two short lines that go from the master cylinder to the proprtioning valve, that is fine for me. However there are 3 other places for lines (the three black arrows in my picture). I assume that the one in the back is for the rear brakes and that the other two are for the front. However I only have one line going to the proportioning valve for the fronts because there is a union down near the crossmember that splits it off into two for the front brakes. Should I just plug one of the holes in the new proportioning valve or do I need to remove the union and run two seperate lines to each of the front brakes?

Thanks for your help.