Midland Ross replacement

[Omni]

Good Morning All
One of the winter projects for the 'Barge' (65 Newport) is to upgrade the brake to a dual master cylinder. the Newport was originally equipped with a Kelsey-Hayes booster. was not able to find a re-builder of these. There is nothing wrong with it, just wanted to renew the parts as it is 50+ years old and I plan on driving the "Barge'. Anyway, a Midland unit was sourced from Murray Park, sent to 'Power Brake Booster Exchange' to be overhauled and re-plated. Got the unit back (looks great) and am now in the process of installation.
My question involves the push rod from the booster. It is adjustable. I have not made any adjustment, the push rod is the same as when I received it from Mr. Park. I could not any mention of this in my '65 service manual. I did however, find a adjustment procedure in a '68 manual. However, it states that you must supply vacuum to the booster. Does anyone have a push rod length with out the vacuum? Should the push rod just be the same length as the depth of the piston in the master cylinder? Or does it really matter?
As an aside, I do have the correct distribution block for the plumbing.
Thanks to all who respond.
Merry Christmas
Omni

 

[65Port]

I have looked through three manuals (64 Imperial, 65 Mitchell and 64-71 Chilton's) and none mention how to adjust. Only disassembly, re-assembly and installation. Maybe it is like a clutch pedal adjustment where there is a tiny bit of free play so the pedal is not engaging in the all the way up position? Curious to see what the answer is here.

 

[FURYGT]

Can you compare the pushrod length to the old booster’s pushrod?

 

[Omni]

Good Evening
Both the old (K&H) and the new (Midland) push rod length with the rod as far back as it can go (no vacuum) measure .912. This is done by eye balling the caliper pointer across the mounting surface. The range given in the '68 Dodge manual is .910 - .920 with vacuum.

Omni

 

[FURYGT]

If the pushrod lengths are the same with adjustable pushrod set where it is at, you should be fine as the pedal range of motion will be the same.