Malwood underdash hydraulic kit for A-Bodies

I just found this also. It's kinda spendy considering you have to buy the hydraulic bearing also. However takes all guess work out of the pedal geometry.

And everything is mounted under the dash. No beating in your inner fender to clear the cylinder and drilling holes to mount something to the firewall.

My only question would be; what if the MC size isn't right to match the slave? Can't tell it it can be swapped for a different one or if there is only one MC that fits.