Deluxe Heater ?

[bj383ss]

So I just restored my deluxe heater, put a new core in it, sealed it up, and reinstalled on my truck. I started working on the lever controls and was checking my notes to see where which cables went to what and I discovered my temperature control lever and door are missing on mine. So I know this will be hard item to find. Will my heater still work with out this? I read in the truck manual that the door helped mix outside air with heated air for temperature. So am I right assuming it will still work just be hot!