I'm putting lifter gallery screens in my other motor and Summit racing has 3 sizes. What size is best for a offshore boat. Stock oiling system but using a Melling 10778 oil pump.
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If it was me I wouldn't use them. If I did happen to talk myself into using them I would get a bigger oil pan. Nobody uses screens anymore.

The oil pan has nothing to do with it. And yes people do still use them. All of the race engines Katech builds for the Corvette race teams use screen in the lifter gallery. The purpose is to prevent any large debris from falling down onto the cam and getting caught in the cam or between the rods.

Someone should make bigger opening screens that are magnetic.

My buddy has 5 Katech motors that came out of the Lemans Corvettes not one of them had screens. And your talking about oil systems with 4 gallons of oil. And the oil pan has everything to do with it if you are going to restrict the flow back to the pan.

I opted to not use them because I didn't want to restrict oil flow and I have 14QT pans.... I would not use them for sure with stock pans just in case...

https://www.youtube.com/watch?v=FapI7XrUGSE

That video is irrelevant.
All it shows it that if you dump a gallon of oil in the valley it will take some time to drain through the screens.

To be relevant, you would need to introduce the exact volume of oil at the exact rate the pump works at and see if that would overwhelm the screens.

Kind of like saying a sewer grate is undersized because a flash flood overwealms it once a decade.

I will agree that the concensus is currently "non-screen".

Ray didn't think screens were necessary either I asked him he said get the oil back ... I doubt it's a huge issue since guys been doing it forever but with my luck it would be issue

I found it very "relevant" to this topic. I'm just a truck driver, so it could be my feeble mind.

A video showing how the screens simply restrict the flow of oil, from a guy who builds some of the biggest, baddest, high powered, innovative marine engines out there, is irrelevant and stupid. Or him simply suggesting in the video, that if you run a high volume pump at extended periods of high rpm, to "be careful". And how the proper screen size, is important. Totally not relative to the OP's question.

What are your thoughts about a big block long stroke marine engine turning high rpm, and the crankcase windage trying to push air up thru those screens, while oil is trying to drain thru them? Is there any truth in that, or is that irrelevant as well?

thank you, for your continued great technical insight you, once again, have brought to the forum.