kelsey hayes part and proportioning valve

ok, n
Like said don’t fret you can use the other block as shown, just have to do some tweaking.
ah ok, i think i see what you mean..i didnt realize the difference there..Ok, so tell me if this is correct, Either get the disk/drum prop valve like Daves and swap it in place of my current on, OR, Keep my original one and just add the hold off valve? Is this correct?