Heater box converted to AC box?

[jjzepplin]

So I have a good heater box and it occurred to me that if I found an evaporator about the size of the heater core that I could just install the and boom I would have an AC box. Has anyone ever done that? This would go into an LS swap truck so nothing needs to be show quality. A while ago I did an entire AC job on a Toyota Echo and when I was looking at the parts on the floor I came up with the idea as the evaporator was darn close in width just the depth was off. I just can't seem to find an AC box in good condition.