Power Brake question '68 K-10.....

[rocketwheels]

...for my 2nd question.....this truck was manual 4 wheel drum, but now has a power booster and what looks like the original master cylinder and proportioning valve pushing the 4 wheel drum set up. Like the steering, this is also super sensitive. The pedal travels quite far before there seems to be "assisted" application of the brakes....just a touch more pressure and the rear brakes lock up.



I'm an old pro at replacing, adjusting and maintaining 4 wheel drum brakes, I'm just not confident about this "conversion". I'm really interested in fully converting to disc brakes on the front, and I am willing to purchase one of those fully matched Booster/cylinder/prop valve combos.....just need to know from what donor vehicles I could scrounge the spindles . I assume they would be different than the one currently on the truck.

I guess if anyone may have an interchange guide or a link to one online, I could find a bit more about correct combos.

Thanks in advance for info . Steve