'67 "brakes" issue
Hello 1st generation enthusiasts,
I'm restoring a '67 Camaro RS. According to the firewall tag, the car came with the optional front disk brakes (first time available in '67, unless the Camaro was a SS (which the front disk brakes were part of the SS package).
The power booster and master brake cylinder are long gone (removed many years ago) and I'm having trouble deciding on the correct master cylinder assembly - with or with out the front brakes "valve" (regulator) that mounts under the mbc.
My GM build manual on page J50 - A2 shows an 11" booster with a dual ported master brake cylinder with two lines going to a pressure switch assembly under the mbc (that turns on a dash idiot light ), and from there the lines go out to the respective brakes at each wheel (one each to the front cylinders, and one to the rear that splits at a "t" at the differential. I could not find drum / drum brakes any where on the page that shows this set up. 1) Is page J50-A2 for the drum brakes at each wheel (no disk fronts)?
On page C60 - A9 of the GM build manual, it shows a valve assembly on the driver's side frame rail which is in the brake line going to the rear brakes. 2) Does this valve reduce pressure to the rear brakes (essentially a regulator) and allows more pressure to be applied to the front drums?
On page J52 - A1, A2 of the GM build manual, it shows everything page J50 - A2 shows, with the addition of valve assembly (regulator) that feeds the line to front disk brakes. (It also denotes disk brakes in the title block of this page). 3) Does this valve reduce pressure to the front disk calipers?
If the valve on page J50 - A2 reduces pressure to rear......... and the valve on page J52 - A1, A2 reduces pressure to the front............ 4) why not just change the valve on the frame rail going to the rear brakes to compensate for the front disk / rear drum brakes as the GM engineers did for the front drum / rear drum brakes?
I'm confused about the purposes of the two different valves. I greatly respect your time and knowledge, and thanks to who ever responds.