It's not a filter, it's an oil/water separator. Looking at your pic it looks like the PCV is on top of the stack coming from the block. I take it this then connects to the intake manifold. The catch can would go inline between the PCV and the intake manifold. Something like this: https://www.amazon.com/EVIL-ENERGY-Universal-Reservoir-Aluminum/dp/B081N3BNXR?th=1
