While waiting for spring, I'm gathering parts and info for my 51 3100. Need to redo rear brakes, and I'm thinking about converting to a dual cylinder. I grew up driving single master cylinder trucks, they don't scare me, but I also appreciate the dual system if a line breaks. How involved is this? Does the master cylinder stay under the floor? I want to stay as stock as possible, but safety upgrades are also in the plan.