[Rattlehead]

I've done several searches, and can't seem to find an answer. Maybe someone can help me here.
69' Camaro. From the factory, car is a manual drum/drum car. I've installed the front disc/power brake kit from Summit. I used the factory distribution block under the master cylinder, and installed a new brake line kit on the front of the car.
This leaves two ports remaining on the dist. block.
The port on the drivers side has a beveled edge to accept a brake line fitting, this is where I installed the rear brake line(pro street car, used a line kit on the front, fabbed the line for the rear)

My question is, what is the one remaining port for? It would be on the passenger side rear of the distribution block. The edge around this port is unbeveled, so it looks like it doesn't accept a brake line fitting. However, it appears to be threaded...any idea what goes there, or do I need to plug this port? All diagrams that I've seen just show one line to the rear and I've never seen this port addressed in anything I've looked at.
Thanks in advance.

 

[Eric Kammerer]

The distribution block has one input from the front of the master cylinder and then two outputs to each of the front brake lines. Then there is one input from the rear of the MC and one output to the rear brakes. The passenger side rear boss is threaded to bolt to the bracket that supports the splitter and bolts to one of the MC mounting studs.

 

[Rattlehead]

Thanks Eric, It all makes sense now!