Call your local Ford Dealer with your VIN# to check the OEM # on your HPOP. If they say you have the 5C3Z-9A543-ARM pump, then this update kit is correct for your application. If they say you have the 3C3Z-9A543-AARM pump, then you have an early 03-04 application and this kit will not work with your truck.
There are no updates available for the 2003-2004 Ford 6.0L's with High Pressure Oil Pump (HPOP) 3C3Z-9A543-AARM. This kit is specifically for the 04.5-07 Ford 6.0L's with High Pressure Oil Pump (HPOP) 5C3Z-9A543-ARM.
The best way to determine if this Fitting Update Kit will work with your application is check you build date & ICP sensor location. Trucks built after September 30, 2003 and/or ICP sensor is located on the passenger side valve cover (above the glow plug control module) would use this kit.
I believe you are referring to the Ford 4C3Z-9A543-(AARM). This would make the truck a late production 2004. This pump is different from the 05-07 pump and would not use the STC HPOP Fitting Update Kit 4C3Z-9B246-F.