I might have to do something similar to this.dmill89 said:The one on the left is the original "sealed-beam" headlight. The one on the right is an Autopal replacement housing that allows you to run a H4 halogen bulb (many other manufactures make a similar housing but cost more). These are brighter and more focused than the stock headlights.
The Putco harness (and other relay headlight harnesses) bypasses the stock wiring and wires the lights directly to the battery eliminating the voltage drop from the stock wiring and further increasing light output.