Can a 2001 2.5 from a RS work in place of a 2.2 ej22 from a 2001 impreza L

I hear the intake manifold will bolt onto the 2.5 engine and work fine. Is this true?

yes, easy swap.

 

check the cam sprockets and if the trigger marks on the back are different swap the cam and crank sprockets onto the "new" engine.

 

should be installing with a new timing belt kit anyway so that stuff should be off anyway to get at the timing belt.