the spring tension may be specific for a VQ25DET as we have positive manifold pressure, whereas every other VQ series motor doesnt (besides the VQ30DET)
so its entirey possible its different. however, FAST it and find out and post back in here!
and yes a catch can prevents the solid oil particles from re-entering the motor via the intake manifold. eventually the catch can would need to be emptied. but if your car can fill one within a few years, you have some problems.
the valve is also threaded at once end that screws into the rocker cover, so youd need one that fitted correctly there.