dssur
+1y
the largest diameter = supply to carb
the middle diameter = return from carb/pump (sometimes its on the carb, sometimes it is tagged off the pump)
the smallest diameter = recovered vapor return from charcoal canister. DO NOT PLUG it, but you can remove the charcoal canister (your truck will smell a little like gas fumes in the summer), you can just leave the line lose (same gas smell) or you can just plumb it to the new cell by adding a fitting to the top. They sell fittings for fuel cels at the roundy round shops.