Searched forums and the multiple manuals I have. Currently De-Smogging my 1981 4x4 and curious what these are called/for. Thanks!!

 

The top picture is a condenser. The other one that is screwed into the intake manifold is a coolant temperature sending unit.

 

Awesome thank you! This condensor what is it used for? I have A/C in my truck but I don't think it's part of that system. Appreciate your help!

 

Does your truck have points in the distributor? If so, the condenser goes with them to send spark to the plugs. Condenser now mostly called capacitors store electricity and release it when needed. They also even the flow of power. They help to keep the ignition noise out of your stereo system.