Installing a new tank from Mancini(does not look at all like the original!) My main question is does the tank need any makeup air or does it get air from the vented gas cap?
Car is a 70 ebody cuda, only line I use is the fuel line. The existing /original sending has a small breather tube that is plugged at this time. The new tank has another little tube welded in the passenger side up high on the tank can I plug this line also?
Also this tank was ordered without ECU.
Thanks

A vented cap is enough.

The 1/4 inch tube on the sending unit would be for a fuel return line...The pass. side tank tube would be the ventline that would run from the tank up through the trunk extension then loop back down to the frame...But as stated you could probably get away with a vented cap...All the lines to run the non-ecs vent line is available if you want to go that route{ }...Here's a previous thread on the routing.. 70 cuda vent line