Which master cylinder to use?1971 Challenger front drum to manual discs

[Chucky3]

Hi,I have a master cylinder question.I have a 1971 Dodge Challenger that has manual front & rear drums.It is originally a 318 car I am converting to a 440.I am also converting it to MANUAL front discs with rear drums.Which master cylinder do I need?The manual with the same smaller size reservoirs or the power disc style with the small & large reservoirs?Will a power disc master cylinder work for manual discs too?Also which valve is required?-The square one or the rounded T-Style?The master cylinder  on the car looks like the power version with the small & large reservoirs but it has drums.Thank you!Chucky3

[John_Kunkel]

Welcome to the board Chucky3.

A disc brake MC will have the larger rear reservoir, power or manual is the same in '71. (some replacement drum brake MC's will have the large rear reservoir) If the MC on the car is correct for drum brakes it will have residual pressure valves in both the front and rear outlets, the rear one needs to be removed for use with front disc brakes.

The '71 has a separate proportioning valve and metering valve but, if originality doesn't matter, you could plumb in a single-piece combo valve.

[Chucky3]

Hi,thank you for your response!Which master cylinder should I go with?-the the power MC or the manual mc for the front disc manual conversion?Will the power mc works just the same without removing the back valve?Does the power need anything altered?They both cost the same.I assume it is easier to just buy the one for power and use same push rod etc?Thank you!Chucky3