In 2003 did Ford use a different diesel that was not a powerstroke in its superduty trucks?

Might be a 7.3 Navistar 6.0 and 7.3 were sold in the f-650 and up you could get catipiler and cummins ------------------------------------------------------------------------------------------------------

Cooper is right, in the F250-550, you could only get the 6.0 and 7.3 as Ford offered the two diesels that particular year. Phased out the 7.3.

To get a cummins or Cat you had to buy a 650 or 750.