I am building a car pretty much from scratch so one thing I would really like is to have a true non a/c setup rather than just the non-a/c box under the hood. my question is this, inside the car is another heater box, the one that the heater core is mounted into.is this box the part number as what is found on an a/c car ?? I assume not so my next question is is the non-a/c interior box on the Firebirds the same part number as on Camaro's?? the car I am building is a Firebird, I have a line on a heater core int box out of a non a/c Camaro and I would get it if I knew for sure its the same box, I know for a fact the ducts would be diff however.