Simplest / least expensive - stay with the drum brakes.
Better is to switch front over to Disc's. Quite a few conversion kits around for this. Need to make sure your Master Cylinder is right one for disc brakes. Adding disc's to rear is much more involved, expensive, and not really warranted unless you are building a show vehicle or extreme power. I'd speak with a custom brake shop about your options if you are not sure.


1940 Chevy KC 1/2-Ton
In the Stovebolt Gallery