Texas Registration

There are two kinds of plates. The Classic plates have unlimited mileage, but require an annual safety inspection.
The Antique plates are restricted to and from meetings, events, and maintenance.
There's actually a third plate that would be a Texas plate set inspected by DPS for the model year of your car and has the same restrictions as the Antique plates.
Some counties in Texas are "EPA Non-Attainment Areas" due to smog levels. Any car or light duty truck registered in those counties is required to have a smog inspection unless the vehicle is 25 or more years old.
Check to see if the county wants to collect sales tax on the car. I had a problem in Austin when I was in the service and remained a Florida resident as a result.
The guys who say you can keep you car registered in your home state while you are in the service are right. Check with JAG to see what you can declare on this one. Rules may have changed since I was in and I wouldn't want to mislead you.