Why would somebody on a chevy site have a cowl inducted hood for a mopar? There are plenty of aftermarket cowl inducted hoods made for other cars besides chevy.
Some one on a Chevy site will have a cowl induction scoop. I have never seen a replacement hood for a '64 plymouth A-body, let alone a scooped hood...so you will likely have to buy the scoop and bond it to your hood. Go to a Chevy site...find a cowl induction hood scoop buy the thing and build it.