You mean to do it yourself, or as in supporting mods.
If you mean to do it yourself, you need basic tools including jack stands (of course). But more importantly you would need a dial indicator with magnetic stand, and a precise caliper to measure your pinion head and shims. And you should get a rear end rebuild kit.
If you mean what supporting mods do you need with the gears, well ... nothing. You may want a beefier torque converter and a shift kit. But you do not need those with just 3.73s. Think more about 4.10s.