Re: brake master cylinder pushrod adjustment
On my 66, that I just added front discs and a manual dual master cylinder.
The new master came with a spacer in the bore so that if fit a power booster. With the spacer removed, the stock manual pushrod from the pedal fit nicely with some adjustment. Apparently the manual pushrod goes deeper into the master so it cannot fall out.
I used the Ground Up front disc kit, less the power booster, and it all fit nicely and works great. I don't have much vacuum, and I did not want the extra stuff that goes with power brakes.
66 Malibu Coupe, home rebuilt 350. Took me 39 years to get her!