Hey Guys, I have a 66 Formula S that already has factory disk brakes. I would like to upgrade my master cylinder to dual chamber. My question is what distribution port to use? The car already has a factory proportioning valve for the rear drums, so I just need a 5-port distribution block. My current distribution block is 4 port. 1. Master cylinder line 2. Left front line 3. Right front line 4 Rear drum line. (It gets split to left/right at the rear of the car) So I think I need a similar distribution block, but with two master cylinder input ports. Does anyone have a part number recommendation? Thanks!