stifz

Just wondering do most of you run return spill lines off your su carbs? I have no return on my su carbs on my land rover - thats how i bought it. Had some trouble with vapour lock but new insulated fuel lines and stopped that. Looking at running a return line - do i need to or not? Do i have to have one or do the floats act as regulators and therefore do away with a spill line. If i do run one does the bore need to be less than that of the fuel line itself. running 8mm fuel line so does that mean i'd have to run a 6mm spill? The set up is twin tanks to a fuel switch then to a low pressure electric fuel pump up to carb 1 then onto carb 2. Advice would be great. thanks