I have a thread on the Handling forum that originally pertained to my Borgeson steering box installation but since that veered away from that and onto my brake system, I'm starting this thread.
In summary.....
In May of this year, I installed the Borgeson steering box. Within 10 days, the cam went flat in the 440-493 and I pulled the engine to go through it.
While the engine was out, I decided to upgrade the brakes.
THAT turned out to be the biggest hurdle of the whole project.
The car is a 1970 Charger. It weighed 3940 lbs and has a Tremec 5 speed transmission.
Before the engine removal, I had 11.75" Cordoba front disc brakes with 2.75" single piston calipers, the Dr Diff 11.7" rear disc brake kit with 1.5" single piston calipers and a 1975 Dart power booster and 15/16" master cylinder. Braking was decent but not excellent.
I wanted to improve the braking to a level on par with newer cars so I ordered a 13" front brake kit with drilled and slotted rotors from Dr Diff and while I was at it, matching rear rotors. He also sent me an experimental hydroboost unit to install, test and report about.
I formed the hydraulic lines for the hydroboost, sourced a Saginaw P/S reservoir with 2 return line nipples, the suggested 79-93 Dodge D-150 2 bolt 1 1/8" master cylinder and screwed it all together.
Right away, the HB provided no boost while the steering worked normally. I bled the brakes and still, the HB was inop but soon, the steering assist began to fail. I put in another pump and the same thing happened again. A 3rd pump started going bad so I removed the HB and boxed it up to return it. I tried a number of bleeding attempts with the HB system with no success so I felt that I gave it a fair shot.
I installed a 15/16" master cylinder in an attempt to make a manual brake system work. I've driven and owned several manual disc-drum A bodies and the braking is excellent with them. I expected similar results from this car but was disappointed in the feel and performance. Pedal effort was very high and brake force was very low. I don't have gauges to test the pressures.
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Yesterday I noticed that when I bench bled a master cylinder, that the front port (which is supposed to serve the rear brakes) got fluid and bubbles first. This surprised me because with the front brakes assuming the majority of the braking force on street cars, I'd have expected the rear port (which is supposed to serve the front brakes) to get the fluid first.

Today I lined up all the master cylinders that I have gathered....

Three are cast iron 4 bolt units. One at 1" and two of them 15/16".....They all had 9/16" front ports, 1/2" rear ports and when bench bled, pushed fluid equally in time front and rear.

Two of the aluminum units were 1.03" and had 9/16" front, 1/2" rear ports and pushed fluid equally.
One aluminum one was 15/16" and had weird 3/8" ports. The front reservoir was longer but the whole reservoir was sloped.

It pushed fluid to the front first.

The final two MCs are the ones I've been working with lately. Both 15/16" and 1 1/8" units have identical ports and push fluid to the front reservoir first.