Semi Complicated electrical scenario

[kbaker214]

Ok guys, not sure if this is the right place to ask but I am going to take a shot.  A good friend of mine is building a 41 Chevy Coupe.  He is using the motor and trans from a 04 Tahoe.  He has someone that is programming the computer and making a harness for just the essential things to make the car run.  Since the 04 Tahoe is wired in a way where everything is hot and a ground is sent, is there a way he can still use the heater control, blower motor, etc?  I didn't know if he could somehow postively wire any of the controls so they could still be used.  He did modify the factory heater box to fit the vehicle so it does have all the same actuators.  Any help of direction to go would be awesome.  Thanks!