Don't know if ford or any aftermarket supplier does have a loom kit already pre cut for the 7.3 but it is pretty easy to just buy the right size (colour of your choice) and replace one at the time. And its probably cheaper to DIY
Unless I'm way off and didn't get what your asking
If you're thinking about replacing the whole harness, if you can even find the right one it's going to cost over $500 from Ford.
If the split loom is all that's cracking, then grab some at the auto parts store (various sizes) and a roll of electrical tape and fix it yourself. Do one section at a time to keep it in the right shape.