Yes I know, the stock ones work well. However. When I bought my 33 3 Window I noticed it seem to have 37 Brakes on it. Do these seem to be a direct bolt on item for these years, interchangeability? Weighing options on this car, and hydros are in the mix.

The '36 and up brakes can be used by switching the backing plates, using a clutch housing from a truck to mount the pedals or making a mount for the pedals and master cylinder and adding the lines.

Any suggestions on finding a source for the backing plates for the front axle? I alread have the pedal assembley with the master cylinder, and can fabricate the rest from there. Are drums readily available from places like Kanter?

When I bought my '31 Coach, the previous owner had replaced the front end with a '36/37 axle and brakes, as part of his half-finished plan to convert to hydraulics etc.
A mechanic friend and I pulled that front end off and replaced it with the original '31 stuff that came as parts with the car, as I plan to use original mechanical brakes. While doing this, there were some complications around the fit of the steering knuckle (if that's what the curved piece is called?)and the drag link, meaning they were not fully interchangeable. I seem to recall the ends of the drag link varied. Luckily, we had enough parts from the two to make it work.