I built my cars 35-40 years ago, when there were still great donor cars in bone yards. My '64 Polara has junk yard front sway bar, cruise control, power disc brakes, and 1969 Charger rear end. I added factory green tinted glass from a parts car I bought, that also had factory A/C. I added Vintage Air, using brackets, pulleys, and vents from this car, as well.
My '67 R/T benefited from junk yard parts, as well. I bought my car as a roller, with no powertrain. Since the car would never be matching numbers, I decided to build it the way I liked. However, my car is a legit WS23L7 piece. Junk yards supplied a 440 powertrain from a 1968 New Yorker, 4-piston disc brakes, power windows, rear window defroster, bumperettes, Chrysler AM/FM radio, and '67 Charger console, with padded armrest lid.