You need to swap the entire unit. Under the dash: evaporator core-heater box case,ducts,control assembly,wiring, dash pad insert & gauge bezel.To complete the swap, the fresh air vents in the kick panels should be changed. Out under the hood: condenser,compressor,evaporator-heater case,hoses,vacuum ball & valve,ect. You will also need to remove a strip of firewall where the evap-heater box goes (look at the two firewalls once striped down & make a template) & drill a few holes. I'm sure I left out a few things, it's plenty doable, just keep track of everything & take your time. Lorne