Here are two master cylinders with 5/8" bore size according to Summit's website. They don't give any information about the stroke though.
My biggest concern with the way that ABS Power Brake makes their system is the fact that the brake pedal looks low to the floor when compared with the original brake pedal in relative location to the gas pedal. Craig's pedal was similar to how ABS does theirs, however, I haven't heard much feedback regarding this conversion that others have similarly done. Blocking off the air vent and putting it on the firewall is not really a good option for me since I live in a hot environment in the summer, unless I put aftermarket air on the car.
ABS mentioned that they were measuring the pedal ratio from the pivot point on the pedal to the center of the pad as well as where the bolt is through the pedal arm from the booster to the pivot point.
Links to 5/8 Master Cylinders:
https://www.summitracing.com/parts/ceb-130-45402 https://www.summitracing.com/parts/ado-18m1192This Post was from: https://packardinfo.com/xoops/html/modules/newbb/viewtopic.php?post_id=240915