The line that runs from the tank to the vapor canisters is your vent. It should have a check valve in it. You don't want to plug this or you'll create a vacuum in the tank. I usually leave this line intact and route between the starter and transmission. The check valve should not let gas spill out but, you still don't want it to end near the exhaust. The throttle body fittings can be plugged or connected with vacuum rated hose. There's a couple different schools of thought on this plug or balance pipe but, I find either works. You should have a filler over flow hose too. I'd leave that alone and again don't let it terminate too close to the exhaust.