Mike,
FWIW, stay away from the Lionel tubular track. The same hold true for MTH tubular as well. Both are of very, very poor quality from you know where. I bought case lots of all sizes almost thirty-five years ago. Before Lionel started importing the flimsy, cheap poo-poo stuff. And have no regrets doing so.
Pop in over on the Tinplate Forum. There are a few members using brand-new high quality American made Tubular track.