Master Cylinder Power Vs Manual

[70 Challenger Lover]

Are there any significant differences between master cylinders used on power drum vs. manual drum?

My 71 came with manual drums and they work great but I want to add a power booster. The master on it now is the original, rebuilt by the previous owner during the cars restoration. I managed to find the Midland Ross booster and I've already sent it out for rebuilding and replating. I'm currently converting the car to four speed so it makes sense to do the booster addition while I'm fussing with pedals.

When I go to Rock Auto, I see they offer masters for power disc, power drum and manual drum. It makes sense why the reservoirs are different between disc and drum but why two different masters for power drum vs manual drum? They both show having bore diameters of 1 1/16"

I'd like to reuse my original manual drum master with the power booster for a more correct look but I don't want to create an unsafe braking situation.

Appreciate any information you all have on the matter.

[JH27N0B]

From what I recall, they are the same.  The only difference is that the manual MC might have had 4 studs installed on it to facilitate mounting it to the firewall. With power brakes the studs are installed on the booster.
If your master has studs, you can remove them to install it on a booster.

[70 Challenger Lover]

From what I recall, they are the same.  The only difference is that the manual MC might have had 4 studs installed on it to facilitate mounting it to the firewall. With power brakes the studs are installed on the booster.
If your master has studs, you can remove them to install it on a booster.

That's what I was thinking too. The knowledge on this forum far surpasses the rockauto website. I've found similar posts by A body guys and it appears I should be okay.

The fluid is fifteen years old so I think I'll yank the master, detail it and the lines and remove those studs while it's out. This seems like a great time to flush the whole system and make sure the brakes are tip top.

[pschlosser]

The parts book shows, for 1970 e-bodies, the master cylinder part numbers are the same for both power and manual drum brakes. 

For 1971, the same MC is used by several other vehicles for both manual and power drum.  But I cannot find a part # for an e-body power drum MC, but this just may be a parts book typo or my failing to discern it.

[JH27N0B]

This is a table I compiled of original part and casting numbers for drum brake master cylinders a number of years ago for an article I did for Mopar Action.
It's been awhile since I looked any further into the subject, but as far as I recall I haven't seen anything wrong or run across any additional information on it.