New USA track would be my preference. Older track in good condition will work. Stay away from the new MTH track that was made in China. The insulators are the biggest problem. They crack and cause a short.
When you block a person, they can no longer invite you to a private message or post to your profile wall. Replies and comments they make will be collapsed/hidden by default. Finally, you'll never receive email notifications about content they create or likes they designate for your content.
Note: if you proceed, you will no longer be following .