99% you need a new cam and lifters. How many miles, and what was the lubrication habits? OCI and oil brand and weight? Ten guys will say I'm wrong like everytime, and chances are this is the result. Is it mostly low rpm and idle shake? Trust me I take no pleasure in delivering bad news, it is sad we all have to deal with this. You might be .01% as in it was bad gas, I hope so.