I need help from you guys. I have a 2002 745i with a blown n62 engine and have a 2004 745i n62 ready to go in. Are the flex plates the same on both the 2002 & 2004 n62? My 2002 n62 has a water cooled alternator while the 2004 n62 has regular one do I need to swap them or can I leave it as is? Any other differences between these two engines?