I swap out any truck I'm sprucing up and intend to drive around with a dual master and vacuum-powered brakes for ease of installation.
I grab the following (should be able to Google these):
- Dorman M39052 Brake Master Cylinder
- 7" Dual Diaphragm Universal Power Brake Booster
- Universal Brake Booster Extension Rod Clevis Kit
- 1955-59 Chevy GMC Truck Frame Mount Brake Booster Bracket (https://www.ebay.com/itm/125152443213) that lets me keep the factory pedal.
- 10lb residual valves for drum brakes (swap out for 2lb on the front when the time comes for disc brakes and add an adjustable prop valve)
- Dorman Brake Power Booster Filter 80195
- 3 feet of vacuum hose
You could keep manual brakes and save a few bucks on some of these parts...but why? Manual brakes work fine, but power brakes work better.
My personal build is a hydroboost setup, but that's more costly and involved, particularly due to the high-pressure lines and fittings needed, vs. a simple 3 foot vacuum hose from the local parts store.