This is my new pedal box setup from CompBrake it's the first one made for a Sierra.
With it came two master cylinders marked up 0.7 and 0.625 but in fact both once out the box was infact two 0.7's

Now i've tried Googling the answer as to the best setup for Master Cylinder size but their are wildly differing claims to the best setup, some saying larger size on the rear some saying larger size up front and of course some giving answers in metric and some in imperial.

I would have thought you'd want a larger cylinder upfront as i'm tring to move 12 pots in total on the front and just 2 at the rear and I obviously want a front bias brake setup.

Happy to be proved wrong just want to make sure it feels right and more importantly stops the car lol.

Cheers Rich