Jaguar designed that motor before Ford had anything to with them. In fact the 3.9L V8 found in the Thunderbird and Lincoln LS (along with a good deal of their suspension… ) we’re all taken from Jaguar and a lot of the parts are interchangable with the “S” series Jaguar and the motor can also be found in the XJ - my dad’s 2000 XJ has the 4.0 (Jag ran 4.0 and Ford used the 3.9)