Blower Motor Block Off Plate?

Does anyone make a blower motor block off plate for a 72 demon? Or even a plate for the fresh air intake hole that feeds the heater box? I removed the factory A/C - heater box from my car & plan on installing a classic auto air setup in the future, but want to know what I can do to block off these large holes.
His name is 1fast383 I got one frome him and it was very nice PM me if you want his phne #