proportioning valve questions

Here's what the new prop valve looks like. It seems like it's backwards from the OE setup...so I think if I cut my rear line behind the distribution block and then use a union I can plumb it into the port coming out the front(1) of the new prop valve. The two ports (one on side(2) and one at 45 degree angle) I can run to each wheel cylinder in the front. I think the white plastic "port" is where the switch connects. Does this seem like a good plan to you guys? Am I thinking about this the right way?