Guys - the previous owner put stock stype power discs up front on my '67. Rear is still drums. In a panic stop, I lock up the rear's first. I'm guessing the guy left the drum/drum junction block in place. Is there an easy way to ID the block, and would you recommend a block swap or one of those in line valves? Thanks!

In a panic stop it will happen. When the car nose dives and transfers the weight to the front causing the rear to get light on the tires. However, if you go to the Inline Tube website they have a complete listing of distribution blocks and proportioning valves. It says that factory drum had a distribution block. Factory disc had a distribution block and a holdoff valve. Later disc brake kits had a single proprtioning valve as used in the late 70's GM cars. These are sold as universals today. I would assume that this is what should have been installed at the time of conversion. Hope this helps, and you see a picture of what you have.

The length of the disc brake valve is longer than the drum brake distribution block. I cannot remember the exact difference, but it is pretty obvious when they are side by side.

Many prop valves look almost like the junction blocks and the only way I could tell the difference would be to have a stock junction block to compare with. One difference (if my memory serves me right) is that the junction blocks have both front lines hooked up to the top of the block, while prop valves usually have them coming out up front and angled up/down. I'd say that this could vary a lot, depending on the type of prop valve.

If you want to install a new one, I would use a prop valve and mount it on the frame (where the original junction block is mounted). Makes for a neat installation, and I hate that I didn't think about that when I converted my brakes. :clonk:

Thank's guys - If I go with the prop valve it needs to be down stream of the junction block - correct? I just can't tee into the rear break line after the booster in the engine compartment.