There are now several options for slowing/stopping you rockwell based rig down as it comes off of high speed crush sessions. Technically you can keep the large drum brakes and modify some giant master cylinder to work, convert over to disc brakes, or run a pinion brake like the old school monster trucks.
I will forgo the choice of running the stock drum brakes. Rip them off and all of the hardware and throw them in the scrap pile. That will save you close to 100lbs of weight off of the axle. You then have two choices really, run pinion brakes or wheel brakes.
There is at least one high end aftermarket wheel brake setup out there that switches over to all custom parts for your Rockwell Axle. My favorite is from Ouverson Engineering. If I was using my rig on the street at all, this would be the kit that I would have. No questions there. The reason I didn’t go with this kit for my rig is simple, it is a little spendy and I was trying to save money. Therefore I went with pinion brakes.
The pinion brakes that I elected to go with were custom fabbed by me and my CNC plasma table. You can buy a kit on ebay, or diy 4x or several other online retailers for very reasonable. I went with the traditional route of the Mazda B2000 rotor and 1986 Toyota Caliper. The only reason I went with this smaller set up versus a more modern 12″ racing rotor set up is due to space limitations. My rig ran stock 56″ chevy leafs up front and I kept the stock spring width to ensure full lock-lock steering. This requires a 10.5″ rotor, or you will end up with spring/clearance issues. If I was running a 4-link I would upgrade to a 12″ rotor just for good measure.
That being said, I will tell you that even with 20″ military double beadlocks (with 5/8″ centers) and 53″ Michelin Tires, my rig would lock up all four tires easily! So for trail/offroad use I went with the pinion brake and have no regrets!