If I were to build another engine today, it would be a roller tappet cam engine. In the late sixties and early seventies, I spent a lot of time and money changing flat tappet cams in a dual purpose race/daily driver engine(s), and good oil was still available then. Today, with the government mandated restrictions on heavy metals and certain chemicals in oil and gasoline, conditions in an engine are not very conducive to longevity of a flat tappet cam, regardless of break in procedures. So, if you are starting from scratch, just g roller, and be done with it.

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