Good to see u making progress with the build! Sorry for not providing any info on my car yet but have been travelling a lot for work lately. First question I have is why you selected the Hammerhead instead of the Dana 44. Are you drag racing the car? If so, I would advise some kind of a pinion snubber to prevent the diff from rotating upward on hard launches. I took the flexible C-beam out of the equation - installed a cross member for the trans and a cross member for the diff. I have a full roll cage and last mod I need to do is tie-ing the center of the diff cross member to the roll cage to make it even stiffer. These mods are a lot of work all together but depends on how you plan to use your car - if you really need them.
Also, now you're at it - are you really going to use the stock aluminum half shafts?
I have seen some nasty breakages even with low powered engines. Does not seem to match the bullet proof center section. Is the Hammerhead same width as the Dana, I mean will the stock length half shafts drop right in without changing the suspension geometry? Good luck and I will be checking the progress.