Swapping a 4.6-liter Ford 3-valve engine from a 2005 through 2009 Mustang into an earlier Mustang, street rod or other vehicle just got easier with a new harness that Ron Francis Wiring is introducing at the SEMA Show.

The new harness can handle a manual transmission or the 5R55S automatic transmission. The harness comes complete and is ready to hook the factory sensors on the engine and transmission to the factory ECM. Wiring for the fuel pump, electric fan and OBD II port is included. The ECM will have to be reprogrammed to suit the owner’s needs.

“We can do more than the factory harness,” explains Scott Bowers of Ron Francis Wiring. “It’s more versatile if you’re using an aftermarket fuel pump with a return line.”

Two styles are offered: a panel/Telorvek and fully wrapped.

“It’s drive-by-wire, so some owners may have gas-pedal location problems and prefer the panel style,” says Bowers.

Prices range from $949.95 for the manual to $999.95 for the automatic applications.

Curiously, the vehicle showcased in the Ron Francis booth at SEMA was so clean that the wiring harness was barely noticeable. The company participated in the buildup of a 1955 Chevy Handyman Wagon for the “Search and Restore” television show. Bowers helped install the wiring and also assisted in the final assembly as the deadline drew near. But underneath the clean engine bay and throughout chassis is a dedicated wiring harness making the LS swap or any other EFI engine much easier.