New member here... 1965 barracuda.

I don't believe a 1965 Plymouth has any "matching" numbers on the engine anywhere. That started in later years, didn't it? Any block of the same "vintage" circa '64-'65 would put the car back in its original "pseudo" matching numbers condition.

I have a '65 Barracuda Formula S with factory A/C (at least it used to have it). That inside unit does not look like any factory vent servo I have ever seen on a factory equipped car, must be aftermarket like the compressor.