97 C1500, what is this box?

[Sactodreamer]

I'm working on the LS swap for my 97 C1500 (originally 4.3L). I'm getting a lot of info from lt1swap.Com but the wiring diagrams there are a little different from my 97. Unfortunately the 97 specific wiring I've found is also slightly different.

But here's my question right now. The wiring going into the firewall on the passenger side for my truck has this black box just inside under the dash. I don't know what's its for and if I need to remove it from the harness.

 

[Drunkcanuk]

Is there any part numbers on the box that you can see? Use them to look up what the part is.

 

[L31MaxExpress]

Fuel level buffer

 

[Sactodreamer]

Fuel level buffer

Researched it and that's what it looks like. Guess I'm keeping that for the swap. Thanks!