Sealant for rocker box to head?

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If you had your rocker box off the head, what sealant did you use when you put it back on? It's a machined surface so figured it should be something like loctite 518 anaerobic gasket maker. The manual says to use a Kawasaki p/n but surely there is something local out there. Because of the tight tolerance I wouldn't think you would use a Permatex high temp silicone but it may be ok for it. When I took it apart there was hardly any sign of a sealant on it. It was very thin whatever the factory used.
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