Check out the early Mustang wiring harness from any of the Mustang suppliers. You don't need to change out the fuel pump, just regulate it down to the 5-7 pounds of pressure your card will be happy with.
Check out
www.broncofix.com for the conversion steps for a bronco to efi and then just reverse engineer the wiring from your efi harness. You can basically get rid of 80% of the late Mustang wiring and just keep the basics (guages and ignition switch).
you will need to change out the distributor and coil also.
Doc