Looking to upgrade the headlights in your 1999-2004 Super Duty? The headlights found on 2005-2007 Super Duty's are a great option. Not only do they look better than their predecessor (1999-2004), they direct light much better too. Since the Ford Super Duty cab and body panels are essentially the same between the two generations, swapping in the newer headlights is a fairly simple task. Parts can just be swapped over with no modifications needed, except for the headlight wiring.

The 1999-2004 headlights used 9007 style light bulbs, while the 2005-2007 used 9008/H13 bulbs. You'll need to either wire in new connectors or adapt them somehow, as the connections are not the same. The easiest and cleanest way to do it without the need for specialty tools? The Riffraff Diesel 9007/9008/H13 Conversion Harness Pigtail Set. This conversion pigtail set allows 9008/H13 bulbs to be plugged into 9007 style sockets. Simply plug the pigtail into your existing 9007 light bulb socket, and plug the 9008/H13 bulb into the other end. Install the 9008/H13 bulbs into the new 2005-2007 headlights as normal, and boom, you're done. The headlights will operate just as they do in 2005-2007 trucks. 

Check it Out: https://www.riffraffdiesel.com/9007-9008-h13-conversion-harness-pigtail-set/