I here a lot of people talking when you upgrade headlights you need to upgrade your harness well i got the sylvania silver star ultra 9007 for my 04 f-350 would i need to upgrade the harness

 

I put the Sylvanias in my 2004 F250 over a year ago with no problems. Ihaven't noticed wires getting warm when the lights are on. Go ahead, I like them.

 

FYI. The ground wire pin - the center pin on the H13 9008 headlight will burn when using higher wattage or brighter bulbs.
On my 2005 -
I replaced the OEM sockets with this
H13 Plug-N-Play Heavy Duty Harness [CIR-9104] - $17.24 : Car Lighting Headlight Bulbs Xenon Halogen Upgrades, AutomotiveLightingUSA.com

I should have installed these at first, but since I trashed the OEM sockets. I cut the socket end off the kit and replaced the OEM sockets with crimp connectors. Worked great.

On my 2005, I decided to install a PIAA system. Picked one up cheap at a yard sale. Cut off the sockets and installed the headlight socket (2) and one male pin to connect to the OEM harness. Now that really works great Power direct off the battery.

 

My 2004 has had them since 2004 and they have not given me any trouble. They are brighter than any headlight on anything I have ever had before.