Trans swap clutch master hydraulic knowledge needed

I'm looking to combine a clutch master and slave from different drivetrains. I have no idea how hydraulic math works so I'm guessing here. I don't know pedal ratios, can't find them online.

The master that came with my car is 0.75" bore and it combined with a slave of 0.94"

The master that came with the transmission is 0.62" and it combined with a slave of 0.75"

After I'm complete I'll have a master with a 0.75" bore and a slave with a 0.75" bore

It appears that my master will move more fluid than the slave expects. Will that be a shorter/stiffer clutch pedal stroke?

Yes, sort of.  The pedal will be stiffer and the slave will travel further for a given movement of the clutch pedal.    You'll have to shorten the push rod on the master, moving the clutch pedal closer to the floor to prevent over travel of the throwout bearing or pushing the piston out of the slave.

It depends on the pedal ratio (length of pedal divided by distance from top pivot to master cylinder), and any ratio in the slave side if there's a dingle arm of some sort with a pivot opposite the throwout bearing from the slave cylinder.

You can compute both of these with just a tape measure.

I can't figure out pedal ratio and clutch fork yet as I don't have them in my hands. But overall I wanted to check that I had the right idea. I figure I can make an adjustable clutch stop as to not overextend the TOB because the pushrod for a W123 isn't adjustable and has a clevis built in.

It always comes down to gearing. You trade off movement for force. A shorter pedal movement will require more force than a long movement. Doesn't matter if it's pedal ratio or hydraulic ratio, they're basically the same thing. In hydraulics, it's the ratio of areas of the two cylinders that behaves like the two arms of a lever.

What is the car?  5/8 clutch master is the most common, there may be a way to get that.

It looks like both cars had roughly the same hydraulic ratio, so the pedal and transmission ends probably have motion ratios to suit that, so keeping the same hydraulic ratio would seem to be prudent.

Or you could possibly redrill the clutch pedal a little higher, to change its motion ratio by... um.. 5/8 divided by 3/4, carry the two... eh just move it up a little?

The car will have a W123 pedal set. I can only find one size master cylinder and the mounting for it is really weird so I don't see changing it out. I'll look at the transmission side though, Z32