I have pulled an engine from a Crossfire with automatic build date in late 2003. All the used engines for sale show a difference in engines before 2/4/2004 and after 2/5/2004. Does anyone know what that difference is? Now I am wondering if I can put this engine in a later car since I am looking for a donor car. I plan on keeping the entire wiring harness, dash, computer, key fob etc in case I run into a problem, what what a hassle to take apart the donor cor to switch these out.