47-59 Evaporative control system on LS swap

[R&B51]

Installing between the rear rails gas tank on 51 project. Using as much of the C6 Corvette components as I can/need to. He has a black box full of charcoal that I figured out is a fuel vapor recirculation system on closed pressurized systems. Must be something used on most or all new cars?
I guess older vehicles evaporate about one tank of fuel out per year and having this in place keeps that out of the environment, out of the air in your garage.I assume I will not be using a vented gas cap, was planning on using one of the new non-cap doors at the filler that snaps shut on its own.
Questions
Have any of you install this on your LS swap?
Is it necessary for a better performance of the fuel system?
Will excess pressure build without this in place?
Threw in a picture in case that helps
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