go to
www.truckandcarshop.com
Buy the fatory replacement for that years and buy the engine harness and the light harness and the intermedeum that runs to your tail lights and replace the rear tail light harness i did that on my 1965 3/4 ton every thing is so much more briter and every thing has its own plugs just like the factory did NO modifying its all stock it will cost you for all the replacment wires from this place about 600.00 but trust me every thing worksand it looks so much nice under the hood don't cheet your self or the truck the 600.00 is a small fee to pay for a harness that will last you until you die or its a good selling point to tell some one that is has all new factory wireing and plugs and in mine the starter turns over faster the lights are brighter my gauges are brighter my high brites work my horn works my amp gauge works and there is no more hacked wires under my dash or under the hood no more shorts the only thing that has given me problems is after 3 years of use the starter let go put a new one in and every time i hit the key it take 2 turns and it fires
Remmber to change the battie cables to and get the thick ones and have your battery checked or changed from other then that your done after 600.00 and change with the wire harness and remmber to buy the rubber fire wall grommet kit and the one that comes from the fuse block to the light harness and blinker harness put it in some warm to hot water and spay some WD40 on it so the plug can be pushed back in to the garment much more easyer have a good one sam from Riverside Calif