Apparently some of the respondents are confused about the route the OP will be taking. She will be traveling Westbound on the Sunset Limited to SAS and will have to detrain and wait several hours for the Texas Eagle to depart at 7 AM. Depending on the day of the week, the Eastbound Sunset/Eagle will drop a coach and sleeper for the Texas Eagle to take to Chicago (listed train 422). The procedure is reversed going the other way, and it's necessary to arrive on the Texas Eagle at a time that coincides with an Eastbound Sunset Limited arriving several hours later.