Who has Dr. Diff 8 3/4 rear discs? Pt. 2

I don't believe I changed prop valves, my car was a drum/drum to begin with. But is there a way to tell the difference by looking at them?

post a photo of your distribution block. Also check to see if there is a secondary block - valve at the distribution block or further down the lines toward the rear brakes. I did not have one on my 68 Barracuda , but I had read that some mopars have a rear brake hold off valve that allows the front brakes to come to full pressure ahead of the rear brakes set starting to engage.