With Mopar you never say never, but the optional engine for a'66 Newport was the 440. There's no engine bay picture, but I would wager money that it's either a 383 or a 440 there, or it's not factory original.
No as far as I know. The 413 wasn't being made any longer by 1966 model year.
What I understand was that the 413 was finished by early '65 at the latest, and then the 426 wedge was its' replacement, and was used fairly regularly in 1965 C bodies. There is evidence that 426 Wedge motors were used in early 1966 C bodies, until the newly introduced 440 became more plentiful.
I'll bet that car is a 383 car, or a 440 car, with the remote possibility of it being a true 426 wedge car...