can i use 99-06 hvac box and controls in 81-87?

[81chevys]

I have a donor 2000 cab and before i junk it i was wondering if i could make this work in my 81. i saw someone use itbin a earlier model 67-72custom crew but has anyone tried this? it makes a lot of sense to me instead of just buying the underdash kit. I am also wondering if the overhead console with the rear knobs would run this unit instead of using the orig spot in the dash.

any wiring diagrams or knoledge would be helpful.
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[MalibuSSwagon]

If you can fit the HVAC box under the dash and translate factory wiring diagrams to repin the harness into a standalone setup, I dont see why not. If wiring diagrams make you dizzy then you may be ahead by using a vintage air type system.