Please educate me here. I've got this prop valve off of a disc/drum 74 A-body car. I'm running four disc brakes on my 64 Valiant now. Things haven't been right from the beginning. One thing I found was that the master was leaking from the back. Got a new one from Dr. Diff. But the prop valve is confusing me.

Inline tube shows that on some cars the five port valve like mine was some times put on cars by itself and on some it had another one added to it. So I'm wondering if I can use it or not?

http://inlinetube.com/Prop%20Valves/pro_valves.htm

Down the page some for Mopar stuff.

http://www.summitracing.com/parts/SUM-G3905/

I've got this that I'm going to put on also.

The ones inline sells are reproduction ones I believe.

Since 64 Darts didn't come with 4 wheel disks you will need to take a different approach.

I'm gonna cheat and make it a little simpler than it is so here we go...
What a proportioning valve does is cause the front brakes to grab differently than the rear. Basically the rear does not do as much as the front because the weight shifts forward during braking and the proportioning valve helps compensate for that.

Since your 64 never had 4 wheel disks you can't get a factory valve with the correct balance and must go for a custom valve.

A Distribution block simply separates the two brake lines from the master cylinder into separate lines for each wheel. They usually include the switch for the brake warning light.

My suggestion is to buy the inline Street rod 5 port valve Pr101 and the summit adjustable proportioning valve.

Run the two line from the master cylinder to the 1st two ports. The front brakes each get a port one for the left and one for the right. That takes up the next two ports and the 5th port goes to the back of the car. Install an adjustable proportioning valve in the line going to the rear brakes car and a T at the back of the car to separate it to each wheel (use the one already on the rear axle). Finally use the adjustable proportioning valve to adjust the braking bias so that the front brakes lock up at the same time or just before the rear.

I hope that helps.

the problem sometimes is that the modern mopar master cylinder is internally proportioned to 70-30---then someone tells you you have to add another prop valve to 70-30 again----seems to me you enter the land of more diminished returns--the reality is you can run a straight line front and back and you are done---if your master is on the firewall in the normal spot you dont have to use the 2 psi residual valves because you have enough column pressure----bob

If you still want to run the prop valve off of a disc/drum 74 A-body car, you can remove the guts to the prop valve and convert it into a distriution valve like IMGTX wrote about. Under the large nut on the valve is a spring and rubber valve that you remove.

If the calipers in back are smaller than the front calipers, you may not need an inline prop valve on the rear. Thats how mine is.

You were given incorrect information.

Get rid of the disc/drum combination valve in favor of a simple (drum brake style) distribution block with an adjustable prop valve mounted downstream.

Cass, so with this work then?

They're showing a block that is five port (darn near like the BLK246 (which is the one from the 74 car) that looks like they are saying that it's just distribution block. Which is BLK244 from Inline tube. So if I use this one then it mounts the same and the lines aren't really going to need to be different.