Drag Car Master Cylinder and ADJ Proportion Valve

@famous bob Thanks. You are right I keep doing research into going to manual which is new to me. With it being manual do you think the 7/8 will be too much pedal travel? Hard for me to tell without a brake booster. The smaller piston will give more line pressure which I would rather have for the car when staging. Thanks!
Dont know about the pedal travel on the 7/8, bet it would be fine . but mine is perfect on that account.
You will need more pressure for staging with disc brakes , i found that out the hard way, discs dont hold as well on the line as drums , have been my experiance .