Pop that little hose off at the radiator and blow in it. You'll know right away if it's vented or not. If it's not, drill a small hole in the cap to that overflow bottle or in the bottle itself.
Thanks my friend tested it tonight and no venting, will swap the fitting to the bottom to pull or overflow into it and drill a vent hole through the cap or just cut the bottom part off and let the side hole where I did have it connected open.
