adding power brake booster to manual brake 1969 el camino

 

Will I have to change brake lines and add a new master cylinder

 

Yes,and also proportioning valve.

 

Going from drums to discs as well??

 

Yes.There are different proportioning valves for different brake configurations.You gotta start changing lines when you encounter different (after market) proportioning valves.Give you an example:My 69 El Camino didn't have a booster on it,but had disc up front.Was a bear to stop.I believe the m/c was either for power brakes or manual drums,probably a different bore as well.I got a booster and m/c kit from Right Stuff detailing (see below).The proportioning valve is located from a bracket coming off of the m/c now.Originally the valve was below firewall on drivers side.Keep in mind that the original lines going in and out of the p/v have different sized fittings,and that rear lines are 1/4",front lines are 3/16". https://www.summitracing.com/parts/rsd-g81310971