Anyone swap HVAC unit from donor?

Anyone swap the HVAC unit from the donor vehicle?

I have a 97 Van complete donor that I was hoping to use but the heater box looks huge! Any suggestions on a HVAC unit that has worked for you?

I was looking at the Dodge Neon unit which seems pretty small.

I'm keeping the magnum serpentine and AC unit and trying to adapt to a non AC 64 Cuda and mount HVAC unit under dash (willing to sacrifice glove box)

Any thoughts are appreciated!!!