Save your money on the rear disc setup. Unnecessary eye candy.
Unless you are going to auto cross the car you will see little braking benefit over a good front disc setup. The front do the majority of the braking. Just use high quality pads and rotors and keep the brake fluid changed.
Instead, try to find a stronger 742 diff to build. The 741 Sure grip unit will work in the 742. Just needs 742 ring and pinion.
