I have recently managed to get my hands on a bit of a project car.
It has a fuel tank in the spare wheel space but not sure of the setup.

I have the supply which goes to the pump at bottom.
A return at the top.

And another larger fitment in/out? at first i thought this was for fuel sender, but thought about it and relised probably for breather???

If anyone could describe breather set up or what i need to me it would be very much appreciated, i have searched internet for a setup diagram but dont seem to able to find it.
Thanks in advance