03 04 Transmission's are different. About 15mm longer because of a beefed up pump and larger pan. The engine blocks are identical. The torque converter is different. 03 04 is larger. Bottom line is a 4.6 is just a stroked 4.0. Crank, cam pistons ect. It should fit with no problems. Anybody else help this member? Both are Bosch engines. I have a friend with a 4.6 RR short block in his 99 D2. Worked.