How big of a job is it to swap a power stroke from an e 350 into a gas powered e 350? I know the tanks must be changed. What about wiring? does it just plug into existing wiring harness?

 

It's not a plug in. Many of the components on a diesel is not even similar to a gas. Eg. glow plugs or spark plugs, Diesel fuel pup or the fuel pump for EFI. The computers have nothing in common. The factory would not install a wiring harness to accomodate two totally different engines.