2003 Ranger 3.0l and 4.0l had same radiator
Try this when look for alternate sources for a part.
Google: 2003 ranger 3.0l radiator
Go to an auto parts site that comes up as having that part
get the part number and manufacturer of the after market radiator
Google that part number(manufacturers part number)
Go to a site that sells that part number
click on "fitment" and look at all the vehicles that use that part number