There's a good bit of info on doing the actual harness/headlight upgrade on here, but not many pics to show the outcome so you can see the kind of difference it makes.
Here's a shot from the driver's seat showing the low beam pattern of my Cibie Z Beams (7" H4 bulbs) running 80/100 watt bulbs and an upgraded harness with 50 amp relays and 10g wiring straight off the battery. The lights are in my '64 VW bug that has the sloped, inset headlight housings that slightly limit the width of the beam pattern. The beam pattern would be wider in a truck.
Couple of shots of the lights in our '97 S10 with 150mm Hella H4's. Same style harness as above, and same Hella 80/100W bulbs. These have a very crisp cut off pattern on low beam. The light is also very "clear" with no added color, either yellow or silvery blue. Just clear. Notice how the Camry in front of me has a dimmer and more poorly aimed beam pattern. The Hella's have a high beam pattern that is more spread out than the Cibie's, so they don't have quite the reach that the more concentrated Cibie's have on high beam.
Camera brighness set to adjust to brightest area in this pic, the pic is clearer this way but doesn't show the true brightness of the lights as well.
The brighness is set on auto on this pic. The wall is lit up just like that in real life, but the camera couldn't adjust to the light on the camry's bumper so that looks too bright in the pic.
