On the Outbacks , MY 2000 and 2001 have the PCV valve threaded into the intake manifold, with hoses connecting to the block, air box (sometimes) and the valve. The hose connection at the valve is approx 3/4 inch?.Starting with MY 2002 the PCV valve is threaded into the fitting located on the block and a single hose connects to the intake manifold, the hose is smaller, maybe 3/8 inch?. The valves are not the same. There was a mid year change and I have seen a couple of 01's with the later style. When doing engine swaps if you have a newer intake manifold and an older block or the opposite, the plumbing and or hoses or even the location of the valve may have been modified to make it work.
In the attached picture shows the attach point on the block the non threaded is the older style, the threaded is the newer style