JY Hero,
The m/c is a sol lump of metal, & a manual m/c bolts direct onto the pedal assy. It is as rigid as it can be.
The m/c for power brakes bolts onto a balloon/round structure made of sheet metal. That has some flex in it, not rigid.
B-money, i respect your technical prowess on carburetors and all things tuning/induction, but i think you're off the mark here.
i don't think there's any more flex in the assembly than there is at the firewall with the manual master.
my hunch still remains that the braces are there because of the weight and the length of the assembly. when they changed to firewall mounted booster it was much thinner and didn't stick out as far, thus no bracing.
