I would not chance either of those tight connections. I would either take the connections that are 2+ hours....or even fly in the night before and overnight at the DFW Hyatt or ORD Hilton. You indicate you are flying first/business class. If you chose the tight connection and don't make it, I would also assume any flight you are reaccommodated on that day will be sold out in business and you'll more than likely end up in coach. We do ORD-Mexico quite a bit and the flights in J always seem to be sold out before the day of departure....especially on Saturday mornings.