I want to install 12" rotors and PBR calipers on all 4 corners of my 72 Cutlass; parts will come from an '89 C4 corvette. I'm installing 17" AmRacing VN500 rims (they look like Olds SSIs) so rotor clearance won't be an issue. The Vette came with a 7/8" mstr cylinder and the Cutlass has a 1-1/8" mstr cylinder. My biggest concerns (other than whether or not it will stop) are excessive pedal travel and getting enough brake line pressure to stop safely.

I can use a 1" mstr cylinder from a '75 Vette (disc/disc) and use a disc/disc proportioning valve from a '79 WS6 TransAm to properly set the front-to-rear brake bias. The 1" MC has 31% more piston area than the 7/8" MC from the C4 Vette; which means 31% more fluid volume and the pedal will travel 31% less, applying the brakes at a higher point of pedal travel. But with the stock a-body brake booster the brake line pressure will be about 20% less than the C4 Vette brake system.

If I move the booster push rod to the upper hole (typically used for manual brakes) the pedal will travel 8% further (applying the brakes at a lower point of pedal travel) but the line pressure will be 26% higher than the C4 Vette system.

Which approach is the better one? I really hate doing things twice so I'm trying to do as much homework upfront before assembling the parts and making the swap. I'm looking for constructive criticism and feedback. I look forward to everyone's comments.
Thanks!