As a rule, 70 minutes is "just fine". But it does matter where you are coming from. Given that you have an option via Houston I'm guessing it is mainline and not a regional aircraft, but it does matter.
For myself, if I absolutely/positively must make my flight because my timely arrival at the foreign destination is that important, I go the day before into SFO and spend the evening at a hotel, relax and then know that I am not going to miss the international departure. Plus I'm in business so I get some Polaris lounge time. I recently had a booking to MNL via SIN and SFO and the DEN-SFO flight was scheduled to arrive just before the SIN flight. I'm OK if I miss my flight by a day, but even so, I had the DEN-SFO flight moved to an earlier departure to give me a little wiggle room and to have a backup flight that I could take if I had issues with my scheduled flight.

This all boils down to how much risk averse you are.

The act of connecting from domestic to international will be a 15 minute walk MAX depending on what sorta plane you arrive on and which gate you come into. It could be as little as 5 minutes. it is all very doable.