All drum master cylinders typically use a single bore diameter to feed > either end.
>
> Your system should be fine.
>
> Where you would have a problem would be if you used a disc/drum master
> with an all-drum system.
>
> The combination valve should be fine. Drum brakes are set up so they all
> apply the same pressure, The fronts still do a lot more work than the > rears though.
> --
> Steve W.
> Near Cooperstown, New York
Steve, you said, "You may want to consider a prop valve IF the rears want to lock up early." Since they definitely do, I'm considering it, maybe an adjustable one. But since I have yet to get a satisfactory pedal, which is my primary concern just now, I'm considering trying to find a m/c quite similar to mine, yet with a bigger bore--like going from a 1-inch to a 1
1/8-inch. Seems like power brakes tend to have larger bored m/c's than manual brakes. At this point, I know NOT what bore my stock 1967 C10 m/c has. Finding that is my 1st step! (I even toyed with the idea of a disc/disc m/c. Each pedal stroke should then pump considerably more volume thru both outlet ports and hopefully give more "effective" pedal--start expanding w/c's earlier on each stroke--although producing too much pressure simultaneously (about 1000 psi used for discs vs. 600 psi needed for drums.) Then install 2 adjustable prop. valves to bring down total psi and at the same time bringing rears down more so to avoid premature rear lockup. I'd have to also install "residual pressure valves" to keep wheel cylinders from completely emptying like calipers do. Ironic, but adj'l prop. valves I'm eyeing are cheaper than fixed ones! Comments on this toy-of-an-idea?) Thanks, Steve. Pls. add more if more ideas surface. s