So, a couple things.
I'll openly admit, I understand a lot of this in concept, but actually doing it seems really daunting as this is my first project car (did I forget to mention that? lol)
As for the fuel system design, I have some dumb questions. What's a surge tank? I assume it's a tank to keep an amount of fuel on tap if you start beating on the car for a long time and to protect against starvation? How would I need to modify the stock tank?
The 260Z has a R180 diff, no? That's what I researched and ordered to OS Giken LSD to be matched to. The drivetrain components are all confirmed to be plenty strong for this HP goal. What exactly is this top-mount/bottom-mount conversion? I've never heard it mentioned before.
I'll check out Garrett's calculator, sounds like the best move.
What's a BOV? I can look for a quality intercooler, I was thinking a standard air-to-air.
All in all, I want to do as much of this as I can (minus actual tuning, of course) because I want the knowledge. But, I also don't want to destroy my very first project car by forgetting to install a wideband O2 sensor (I don't even know where it would go as of right now) or something trivial like that, so I'm kinda leaning towards having critical work done by the shop I've used all this time. Seems like the really worthwhile projects can be seemingly impenetrable to noobs.