Going to be a nice build!
What tire/wheel combo are you going to run?
What's the focus of the build? Usage-wise?
My .02 would be, do something other than a huge fuel tank under the frame, it will really put the hurtin' on you when wheeling the truck.
If I wanted to expand my fuel capacity, I'd install some of those old school interior side tanks they made for our blazers back when.
(I know of a set for sale right now BTW)
2ndly, no need to spend 5K on an injection system for your 383, a factory TBI package that's tuned up with a chip & better injectors would serve you well.
Great to see another build start up!
You know the deal...keep us up to date and use lots of pictures.