For 1957 NAPCO front brakes, they are from a 1953/54 Studebaker Champion:, see below:
https://www.studebakerparts.comFor the shoes you have to send them your old ones, if you don't have the old ones to exchange you might be up for a wild goose chase.
Shoes:
BRK146-BRK2 BRAKE SHOES or BRK145-BRK1 BRAKE SHOES (make sure to measure yours)
Here are all the parts you need for the self adjusting device (both sides):
1) BRK048 521396 1947-1953 SELF ADJUSTER TIPS (2)
2) 521393-4 SELF ADJUSTING WEDGE LEVER (1) Comes with left and right
3) 521391 SELF ADJUSTING WEDGE, RIGHT (1)
4) 521392 SELF ADJUSTING WEDGE, LEFT (1)
5) 527253 ADJUSTER TIP SPRING WEDGE (2)
6) 521398 BRAKE GUIDE (2)
7) 524028 BRAKE SPRING, RIGHT (1)
8. 524029 BRAKE SPRING, LEFT (1)
I did use the Studebaker parts to rebuild mine, except for the
brake shoes, which I took to a machine shop to get re-done.
It's important that you get the correct washers to go behind the shoes on the cam hold down poles and the ones that go in front, also the C hold down clip. If you don't have the correct ones, and the correct thickness your cam may not line up to hit the self adjusting wedge. Then your minor brake adjustment won't work.
With no shoe first put on
1) 526530 - Flat Washer... then
2) 521413 - Super Thin Spring Washer (continually pushes shoe outward for correct placement)
3) Put on your shoe now
4) Add another 526530
5) Finally put on the C Clip to hold it all together 642522
The drums are hard to find, if at all. I used stock ones and enlarged the center hole for the 4x4.
Brake Cylinders: I couldn't find the the correct ones, so I got mine rebuilt. You could check if this helps:
http://www.napco4x4.org/forum/viewtopic.php?f=41&t=926I finally gave up on the stock set-up, it was just poor. I fabricated front disk brakes as per:
http://www.napco4x4.org/forum/viewtopic.php?f=41&t=608I did need to enlarge the rotor center hole.
I also installed a dual master cylinder with boost.
Everything works pretty good with the new set-up, not difficult but exacting.
don