Magnetic Sensor - Help needed

[Laurence Walker]

I've used a Zemco Performance Timer in my Vette for many years.  It works=
 by counting magnets affixed to the driveshaft with a magnetic sensor, =
then processing the counts into distance/speed/elapsed time to a 1/4 mile=
 and speed at the end of the 1/4.  It also shows time to 30 mph and time =
to 60 mph.  The system works very well and has agreed closely with actual=
 times at the track. Recently the magnetic pickup was damaged and I've =
been unable to retrieve the end of the broken wire from within the plasti=
c potting of the pickup.

I've attempted to contact the manufacturer without luck - does anyone kno=
w where they might be located?  The Performance Timer is no longer being =
made.  However, the same pickup was apparently used by Holley as part of =
their onboard computer used for computing MPG, speed, time, fuel and dist=
ance as shown in their 1990 catalog.  Holley part number is 34-301.  When=
 I tried to order the Holley part, it was unavailable.

Does anyone have one of these in their junk box, or know where to get one=
?
Does anyone know of a substitute, or perhaps the inductance so that anoth=
er may be made?

TIA,
Larry Walker