Will This Heater Box Work?

[69 340 dart]

Has anyone try'd to install the A/C Heater box assembly into a early A {65 Valiant} from a late A [74 Valiant] ? The 74 has the vent mounted under the dash as I'm sure all of you know. The 74 is 2'' wider than the 65 and the fresh air door will go away. In my teanage days we were able to hide a six pack of beer in the air doors. Three in each side. If anyone has attempted this update please let me know.

Thanks
Brent in Az.