Not quite correct. The 4.6L 3V block is a new casting. It is supposedly both more rigid and lighter than the old 4V aluminum block. If you go back and search for the 05 Mustang press releases, they talk about the new block. 05 Mustang Overview Press Release 05 Stang Powertrain press release In addition, a couple of the car rag preview articles on the 05 Stang mentioned that the block was new.