so 2 things.
I agree with the others that smaller diameter will give you more braking force and you should probably pick up the manual master for the 70's corvette. it is the smallest GM one that I could find.
2nd, the pedal take up you describe does not sound right.
either you have some play in the front discs that you don't see, causing the pistons to push back, or there is something drawing the pistons back in.
but please explain how you know it is only the take up to get the piston to the disc?
I have moved the pedal by hand from rest to its take up point, and between those points I can hear the brakes move. When I have the calipers flipped up and held on with a C-clamp, I can see the clamp screw end move slightly in sync with the sound as I have to start pressing harder.
