Brake Questions - Help

With that engine and a manual trans, things can go bad in a hurry with an inexperienced driver. This is because with high-compression, the engine generates a lot of compression braking, and it all goes into the rear wheels....... making it easier for the hydraulic brakes to attempt to lock them up. However, it cannot do that without stalling the engine.Experience tells us WHEN to push the clutch pedal down to prevent those things from happening. And the P valve tries to make the car safe for all concerned, by limiting the rear line pressure to IIRC 85% of the front, and the factory sized the rear brakes to limit their capacity to about 15% of the total. As you can see, there is a tremendous amount of braking potential to be had in the rear brakes......... for performance driving.

Your valve is NOT a combination valve.
Your valve is strictly a safety switch/distribution block.
In a C-valve, that Texas shaped part will be an integral part of it.
As for the block at the back; I have never seen it be anything but a splitter.

215/60-14s, 340HO, and manual trans,
Should never appear in the same thread.

That is great information, not ONLY Is it a 340HO 4 speed, but has a large cam in it (still flat tappet lifters I think), a 750 Edelbrock 4 barrel, AND fender well headers (yeah I said it). So the car needs the brakes to work right. To round it out, it is 1 of 52 of these types of cars they made in 1969 (low production number) so I need it NOT smashed. And I need to custom bend the lines from the MC to the distribution block to got back to the firewall then down and forward to miss the headers. Kinda crazy. Finally, it is a factory power convertible.