I used a Hot Rod Wires harness in my '56 and have another waiting to go in my '54 GMC pickup. It has GM color coded wires, larger wires than stock on things like headlight, alternator and ignition circuits and plenty of length to the wires for custom installation.

"It's just a phase. He'll grow out of it." Mama, 1964

1956 Chevy 1/2-ton 3100
1953 Chevy 6100 "The Yard dog"
1954 GMC Suburban Now with a new proud owner.