Is there a vacuum line attached to the fuel pressure reg and where does it go on a 1997 fi 350?

Yes, on a 1997 Ford F-350 with fuel injection, there is a vacuum line attached to the fuel pressure regulator. This line typically connects to the intake manifold, allowing the regulator to adjust fuel pressure based on engine load and vacuum conditions. The vacuum helps ensure optimal fuel delivery under varying engine demands. Always consult a service manual for specific routing and details for your vehicle.