Water filter...?
We debated this issue several months ago and really don't think it's necessary, unless you ride in really dirty water. If you do, you'll need to get a clear side strainer so you can moniter it for debris........
My engine (1997, 787) is the original engine. I pulled the head last year and was surprised at how little sand debris was actually sitting inside. Then realized that because the water enters the block at the exhaust manifold, at the bottom of the block, it pushes debris up and out of the flow path.......
So, to do so, may restirct your incoming flow.....when it's really not needed.:cheers: