Blend actuators

Those would be the mode door actuators. Blend/mix actuators control temperature, Mode doors control direction. In your case there are two mode door actuators, one controls the air from the dash and defrost and the other handles the floor ducts.
They are both attached to the plenum box that mounts to the back side of the dash, you remove the entire dash to get to the plenum itself.

If you decide you want to tackle the project plan on a weekend to take it apart and put it back together, and you may want to get a one year subscription to either www.alldatadiy.com or www.eautorepair.net so you have the full instructions about what and how to get the dash apart.

Video showing the location.
https://www.youtube.com/watch?v=4g-ONeoFkgQ