Hey there on my 04 powerstroke I use to have heat working everywhere: floor, vents and defrost but when I got it back from the mechanic shop I only got it coming from defrost and nowhere else. I've heard a couple different problems from the vacuum line to the EGR vacuum solenoid. What else could it be? Thanks for looking and giving me an answer

 

Blend door issue, but by the sounds of it, it has something to do with the work you had done getting the new motor installed.

 

Vacuum problem. Make sure the little gray line is plugged in on the heater control valve. These trucks default to defrost with no vacuum.

 

No Vacum. You had heat before the engine work and none when the truck came back. Disconnected or broken vacum line or the pump is not running.