<VV> Harmonic Damper(Not balancer)

[Smitty]

Smitty Says;  I don't know if is magic or not, but the 6th harmonic 
torsional  vibration of an Early crank is shown in the SAE papers as 
4,300-4,400 rpm.  Not much danger there for the average drivers engine. 
When they changed the stroke in 64 that obviously changed the max vibration 
point.  I have read (and maybe one of you can tell where the statement came 
from) that with the Late engine, destructive vibrations were noted as low as 
2,700 RPM.  If that is the case, then a cruise speed of 60 MPH is pretty 
close.
Most of us and that includes you, are not qualified to say why they left the 
damper off of the Late 95 engines.  Many factors come into that other than 
stroke.  Even the slight difference in the sharpness of the impact of the 
higher compression forces would affect torsional vibration.
As a survivor of a broken crank at Midland South Dakota. I am putting 
dampers on all my Late engines.