Making the connection shouldn't be a problem... the SCL airport is fairly small and quick to get through immigration/customs. The national flights depart from the same terminal. When I was in SCL a few months ago, it took me 10-15 minutes tops from getting off the plane to the national terminal wing (only had carryon bags). Don't forget to pay the $65 reciprocity fee if you haven't already; the desk is to the left as you come down the escalators before immigration.