I posted a week or so ago about changing the lash setting on the M4F in my 261. The recommended setting on the cam card of .014 and .016 worked best for me. Trying the stock 261 setting resulted in poor performance on my engine.Our other 261 is a stocker with the original "Corvette" cam as used in 261's. The factory listed lash of .006 and .018 works best on that engine. The Corvette cam and the M4F are similar in duration but the M4F seems to have a more aggressive opening and closing profiles.
I have found on the M4F, the most accurate settings are done one valve at a time, the lash checked when the companion valve on the same cylinder starts to open.Using the traditional method of rotating the engine until the number one cylinder is in firing position ,then adjusting #1 intake,#1 exhaust and so on leaves a wide variance in clearances. The settings are done warm, like after a 1/2 hour run.Once set correctly the valves stay in adjustment for a long time. The Howard cam is busier sounding than a stocker, but the valvetrain mechainical clatter is vintage hot rod music.
