you need that little metal plate. Or any plate to cover that.
I learned that the hard way, and Oil (lots) just poured.
The second time though, after I installed the baffle and the manifold, no more oil. My oil solution was solved.
BTW, everything that I just said, or wrote, happened to me just this week. (Monday)
I highlly recommend getting that baffle, or else, you will see lot's of oil.