I usually fly UA, so I need a little help understanding the rules.

I understand from research here that the longest connection you can book on SWA is 4 hours, and have found how to do that. Is it possible on a business select fare to change to a LATER flight on the same day?

Flying LIT-DAL-HOU, and trying to spend more time in DAL, so there are a ton of later DAL-HOU flights. Just need to know if this is possible to do on arrival in DAL, or if the 4 hour maximum is absolute. Thanks.