had written: "Strangely, although everything else in identical, the mounting studs were 5/16 by 20 SAE. Were these originally ordered by some American car maker, do think? Any one know?
Another related issue. I once put 1750 ATEs under my Giulia 1300 TI, but retained the single circuit MC rather than install the 2 circuit tandem MC. I had rear lock up at the limits of braking. Those thinking of reverting back to a single circuit system should think about why the 1750 MC has different bore sizes for front and rear."
Yea, the Bosch booster that I got recently (I think mine came via IAP) also used 5/16 studs. Weird. My guess is that since the original Bendatalia boosters went on cars with Girling (or is it Dunlop?) brakes, that they probably also used inch-sized hardware, and Bosch chose to duplicate that thread on their replacement product.
Were you running a pressure limiting valve on the rear circuit? Without one, I would expect your rear brakes to lock up before the fronts. Keep in mind that the hanging pedal Alfas, cars that also use ATE brakes, have a single bore in the MC. Yes, it is a 2 circuit MC, but with the same bore, and thus the same pressure, front and rear.