Not that much too it really. I chose that master MC36239 from 1967 Impala listings knowing that was the first year for dual cylinder and it had the spring type lid retainer ,not the bolt on one. Once installed i ran a new 20 inch long{ to make a loop } 1/4 inch line to the brass junction block from the front port of the master. I then put a brass plug where the rear line use to run from .Then I ran all new line from the rear hose to the rear port on the master cyl. I used two 60 inch lines to get close to the front and then a 30 inch line {to make a loop}.
No prop valve or valve of any kind {brake warning light}