This is a time consuming project but it is one that is well worth the effort. The big question is which way you want to go with the electrical system. Do you want to update it with more circuits and such, or do you want to go with straight stock replacement?

I have not done anything other than using stock replacement harnesses, and for the '60-'66 trucks there are a lot of places that carry the harnesses. I just bought a bunch of harnesses from Classic Parts for my '63, and they slap right in just like the old stuff with all the same connectors. Like Achipmunk said, check the Links page for electrical vendors.

The thing with the wiring is to plan it out and know exactly what you want to do before jumping in. Take lots of pictures as you work on removing the old wiring so you can refer back to them to see how things were routed. It isn't all that hard to replace the wiring, just go slow and don't rush it and you will have it done in short order.

1963 Chevy C20 Longbed Stepside
1978 Chevy K30 Custom Deluxe