5.7 90 T A WITH 94 5.7 CAMARO ENGINE,SPEEDOMETER not compatible help

can anyone tell me where I can find something that would make the speedometer compatible with a 1994 5.7 engine from a camaro on a 1990 5.7 trans am, I know there is some kind of harness you can buy, but
don't know what and where to look, I almost done with the restoration on my T A, and thius is the only thing left that doesn't work, thanks
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Your speedometer is driven off the transmission not the engine. If your using a 1994 transmission with a 1990 Mechanical speedometer, it will not work. If you have a electrical drive speedometer, you can adapt the harness. The way to drive a mechanical speedometer is to use a 1993 tail housing and output shaft, which used a mechanical speedometer drive.
Now if your referring to your Tachometer (RPM's), you just need to find the tach signal output from the optispark unit, and connect it to your clusters tach signal input. Charles
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I thought all speedo's by late 80's were all electrical. Did GM go back to cable driven speedo's for the 4th gens?
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Most old style Electrical Speedometer drives are the same as mechanical speedometer drives. This means you have a gear to gear set up, with a changer box. The changer box converters the mechanical input in to a electric signal.
Later cars went to a system where no mechanical drive is used. Instead it uses a VSS (Vehicle Speed Sensor).
And no, in the late 80's and 90's a good number of cars still used a cable driven speedometer. Charles
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