Thanks all - I have decided to install without the proportioning valve since I never had any real complaints about it's braking previously.
A follow question for you guys:
The original Master Cylinder included a collar that guided the pedal push rod keeping it centered on the plunger. BUT the new Master Cylinder does not have the collar... instead it would appear that the push rod is just expected to be installed snuggly between the heim joint (swivel ball) and this 3/8 dimple on the plunger - does that sound remotely correct or am I missing parts from the vendor??
Thanks again!