I was at NAPA Auto Parts today for something else so I asked how much for injector O-rings for a 2012 F-150 5.0L. It was $2 and change for a set of 2, advertised as upper and lower kit for 1 injector, so I bought one. They are NOT the same as our Jag injector O-rings. The O-rings from NAPA for a Ford injector are both the same size. Measuring carefully I think:

Upper Fuel Injector O-ring for the Jag is a US/British standard #203, 0.296" ID and 0.574" OD (=7.5mm ID and 14.6mm OD).
Lower Fuel Injector O-ring for the Jag is a metric 3X8.5, 8.5mm ID and 14.5mm OD.

The F-150 O-rings from NAPA were both metric 3.5X8, 8mm ID and 15mm OD. Within a half a mm in all dimensions of the OE O-rings so I'm not going to say they wouldn't work, but I have my doubts now about the GB Remanufacturing list of compatible vehicles.

 

dk53, this is where possibly going with the same year, but going with a different model may work. So, in your case, ask about the o-rings for a 2005 Ford F-150 5.4L engine. The 2012 may be just that little bit different that for the F-150 it will work, but you have gone a few too many jumps to fit the Jag. That is why I tend to reference the LIncoln LS. The two motors share a lot of parts and I know for a fact that the o-rings do match up.

A funny side note, I made a comment back in 2010 that the o-rings looked a lot like what was used on a F-150. Little did I know........