I forget who the supplier is off hand, but there is a direct plug & go wire harness for the '60-66 trucks. This could be done in 1 day, maybe 2.
I believe it's in the Classic Trucks magazine if I remember correctly.
I've rewired my '62 (from scratch) over 1 weekend, the first day was the cab, second day was under the hood, headlights, and taillights.
I did this with the help of the shop manuals (supplements 1&2)
David