Not with a drum brake car.
A factory disk equiped car built after Jan 1 would have come with the combo valve.
When converting the fronts to k-h fixed calipers use either
the original safety with a proprtioning valve in the rear line (as was done '67-69)
or
a combination valve.
Factory valving works well with matching factory rear brakes; or depending on shoe and pad linings, tires, pavement, etc., sometimes slightly smaller rear wheel cylinders.
