Another Brake Conversion ???

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I have a 70 Charger 500 with 4-wheel power drum brakes.  I'm thinking of getting a Wilwood or SSBC front brake kit.  The Wilwood literature does not indicate anything about a need for a new power disc master cylinder change.  Will I need to get a new master cylinder and if so, will a stock Mopar power disc brake MC for a 70 Charger work?  Will a new proportioning valve also be needed?  The SSBC kit seems much more complete and has larger rotors, but I've heard of problems with the fit of their master cylinder.  Is this accurate?  Thanks for any input or recommendations.