Can I use the OEM Dakota fuel pump?

Yes, it works. I have no idea what he did. I have a
8 3/4" differential so I'm clueless as to were the pick up os located.

The post that Dion put up has some good pics of the fuel pump and dash as well.

I know that he had changed the transmission, but I assumed it was another 46re that went in. Maybe it gets its signal from the transmission.