Maybe someone out there knows the answer to this one or can steer me in the
right direction to find the answer. Just bought a Stewart Warner 5" electric
speedo (for alot of reasons, one of which was to be able to recalibrate to
handle the non-stock drivetrain). My '49 3600 is pushed by a turbo 400, a
10" posi with 2.73 gears and a pair of 255-70x15 meats. The calibration
instructions are based on mounting the speedo, driving a measured 5mile
length of highway, calculating any discrepancy with this distance on the odo
and finally finding a cross reference in the supplied table (you then get to
repull the speedo to reset the "code"on the back of the speedo before you
button it all up once again). I called the "engineer" at SW tech support to
find the final drive gear ratio that the unit is factory calibrated for so I
could just recalculate mine based on the above parameters and set the speedo
before I mounted it. He told me that was impossible to do and that they
don't know what the speedos are set for, just how to adjust them if they
don't measure the prescribed 5 miles. Is this really rocket science? (Or
maybe more like reading tea leaves.) Anyone know how to work out this
calibration or am I out in left field? Thanks for any help available.
Jerry B.
'49 3600
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