I found the timing card for the Howard's M4f cam I installed in my 261 6 years ago.Says set valves at .014 and .016 hot. Today I reset the valves to .008 and .014 hot. This setting killed the mid range although it was just as smooth.Checked the settings again, still the same. So I reset the valves to .014 and .016 hot.Much better, the difference is quite noticable, runs great as it has for 6 years.Its my assumption that valves are adjusted hot, that way the valvetrain components are temperature equalized. The factory manuals go to great length about warming up the engine prior to setting the valves.Perhaps Howard's changed cam profile and the lash settings.Set it the way it wants run best.
