It seems there are all sorts of options for 47 and up. But for the 41 to 46 there are no master cylinder conversion kits or replacements. It must be due to the odd mounting of the MC on the 3 speed transmission. I would like to upgrade to discs and dual MC, but there is nothing that "bolts in".
The solution here is to get the clutch and brake pedal setup from a larger truck of the era. The MC was frame mounted, with the actuator rod facing toward the rear of the truck.
The set up worked like this, when the brake pedal was pushed, a rod and clevis was attached to it in a way that created a pulling motion on the rod. This rod pulled a frame mounted lever towards the front of the truck. A shorter rod was also attached to this frame mounted lever that would in turn push the MC.
This sounds really complicated, but it is really a simple setup. Many after market frame mounted MC brackets can be made to work with or without a booster.
