What is this for?? and do i need it?

[DURRTY]

This has 3 fuel vent lines going to it and also it looks like at least three more fuel(return, vents?) lines going to the front of the truck.
The genius PO hooked one of them up to the front diff vent line!!!!! I'm sure that the fuel vapor is great for the gear oil???!!!!!
the other doesn't go past the frame at the front wheel just broken rubber at the end of the steel line, and the other is the line to the pump and carb. I can post more pics if needed. but what is the deal with all the vent line or whatever it is and how much of it do i need to make it run properly. I have the body off and started to bend new fuel line, which is time consuming so if I don't really need to run all that line the to the front of the truck im not going to.

thanks