oil with zinc for 1977 350 chevy engine for 24'searay

[wakina]

Most all auto parts stores carry Lucus oil zinc additive and you can add that to your crank case when changing oil. A good oil would be Shell Rotella 15w40 formulated for diesels as it has all of the additives needed for a marine engine to fight the corrosion that a marine engine is exposed to. I just repowered my boat and once again the engine supplier recomended the Rotella oil and the Lucas zinc additive which helps when you have a regular lobed (flat tappet) cam shaft found in older engines, it is not needed with a roller cam. The Rotella oil is available at Walmart in both quart and gallon jugs, also at most auto parts stores. I have ran it for years with absolutely no issues. I have repowered twice over the years but never due to an oil(lubrication) problem. This oil has served me well.