Is the motor out of a Crown Vic
2 Answers
I think you will have problems due to ECU incompatibility and other issues. The 2003 has a 2V engine and the 2008 should have a 3V engine.
You'll also have trans compatibility issues in addition to the ECU ones. If you swap over everything to do with the drive train including harnesses and computers and make it work with instrument cluster you'd be good, very little changes size-wise.