2004 Chrysler Pacifica when doing a tune up do I.

It's not smart to not replace the gaskets because a tiny vacuum leak will affect the oxygen sensor readings. They will report a lean condition and the Engine Computer will keep on trying to add more and more fuel in an attempt to solve that.

Typically downgrading options like the mirror will mean fewer wires in the connector but the connectors are typically the same. The power direction should be the same. Still, you'll want to compare the plugs first to see if they're the same.