Putting the case back together is pretty much the reverse of taking it apart. If you have a vacuum pump you can confirm proper operation before you reinstall it. The next few steps can be done with the assembly sitting on the floor of the truck.
First picture shows the adjustment point for the heat flapper door.
With the selector in COLD (picture 2) I adjusted the cable so that the door was completely closed (picture 3).
With the selector in HOT (picture 4) the flapper should be fully open (picture 5). Note exposed heater core.
The ports on the new actuator are larger on the new actuator than the old one (picture 6), I made adapters from larger tubing and barbed connectors.
