Does a 2003 3.5 liter engine Chrysler 300m block fit with Dodge Intrepid head and work?

No, a 2003 Chrysler 300M 3.5L engine block will not fit with a Dodge Intrepid head, even if it's also a 3.5L. While both cars used 3.5L engines, the engine design and head castings are different enough that they are not interchangeable. Trying to force a fit would be impossible and likely cause significant damage.