Speaking from bitter experience from my early days at N-V, you can make the drum brake work quite well, but not unless you add the stiffener kit to the backplate. I did the early testing to try and figure out why the brake was such a 97lb. weakling. The problem was that after the shoes contacted the drum, no amount of additional force on the handle would improve the stopping distance. At rest, it was possible to pull the brake lever all the way until it touched the twistgrip.
I did tests with brittle lacquer, a special clear paint that would flake off if distorted. We found that the brake backplate was too flexible and additional force applied to the input distorted it instead of increasing the force on the shoes. Management decided that a disk brake would be better and effort was put onto that project, expecting a quick result.
Unfortunately, the early designs tried to have a sliding disk, with a non-moving caliper. Every method we tried failed very quickly because the force being applied near the outer rim of the disk cause it to tip slightly and jam the sliding mechanism closer to the center of the disk.
Becuase of the time spent trying to get a disk brake to work, development of a stiffer backplate for the drum brake wasn't tackled immediately, and many of the first 2 years' production had the original drum set-up. I think the first stiffener kit was an outside vendor idea, but it was introduced in production after I quit the company. If your brake isn't stiffened, then I would STRONGLY advise you get the kit and do it.
Changing over to a disk brake isn't very complicated, but it is expensive. Folks on here who have done it will be able to give you more information.
