I rewired my 49 without a kit. The schematic in the Shop Manual, good wire stock, connectors and a good crimping tool were all I needed.
I removed one wire at a time, duplicated it and replaced it on the truck.
Take photos, take notes as they all help.
Frankly it was quite easy to do.
BTW the wire gauges in the schematic are for 6 volt so if you change (why bother?) to 12 volt you can use a smaller gauge wire.
