What Bore Master Cylinder Do I Need?

That's true but that isn't what I was getting at and never said anything about moving more fluid through a given line size. I was just giving examples of what happens with big vs. small bore size giving the same pedal effort. Moving more fluid through the same line will cause higher pressure but it takes more pedal effort to build that pressure.

ok then we are on the same page. Im not worried about the effort as I decided to run the dual 8" booster as the 7" wasn't going to gain me where I was hoping.

I ordered a dual 8" booster and 1.250 master so i'll get it installed when I get a chance and let you guys know how it goes. They seem a common upgrade for chevy's with factory mushy pedals so im not to worried.

will update