I'm rebuilding a 1974 charger 400hp 4spd car. It does not have a/c. I have a mostly complete 74 charger 318/904 car with a/c. Also have access to a 1973 318/904 satellite which I believe has a/c. This is the car I would prefer to rob from. Did a little looking and the fire walls are different, blower motor mounts different, and heater hoses are in a different location, and likely more stuff I missed. I am assuming to do the swap to my 4spd car I would need a dash, heater a/c box and fire wall section, controls, ect, which I have. How much of the fire wall do i need you think? Can I just cut out the passenger side area roughly 17" wide, or is this an entire fire wall swap with other unforeseen obstacles? The car has been blasted and is sitting on a rotisserie, so now is probably the time to do it. Though I dont absolutely need a/c, it would be nice. This a relatively rare car for 74, but I dont think its overly valuable, so some departure from how it was equipped from the factory shouldn't be a big deal ??? I looked up a/c systems from classic air and vintage air, nothing for 71+ b body Thanks.