I am looking to put this kit as weel as new LED headlights on my 68 bronco. It has all original wiring, do I need to replace with new wiring for the LED exterior kit and headlights? Thanks.

No, or not normally. The cluster bulbs are direct replacements for the originals. The exterior kit comes with one low voltage flasher for LED's, but a second may be needed. LED headlights are usually no problem.