I owned a '70 U-code cuda, that had two BS and the original fender tag. The fender tag and both sheets listed the engine as E87 440+6bbl. I still have copies of both sheets. I sent all the docs to Galen back then (1996), and his take was that the U-code VIN ruled out the 6bbl engine code. The door had been changed out, so the sticker was long gone.