Vq35de s13 swap question

[nddavis2]

Trying to help a friend swap a vq but have come into a snag. He would like to drive the car in the winter so he needs defrost/ heat. Ac isn't much of a concern at this point. None of the threads I've read have information on this nor mention if the even run the heater hoses to potentially have it. Seems most threads the op didn't finish the installation and haven't logged on for years. Does anyone here have any info on this? He's using stock ecu with mats disabled and the car runs though it has some codes and messed up looped coolant lines that don't run to the firewall for heating.