i am in the process of installing a 4l80 manual valve body transmission. the transmission has 2 electrical connections on the side of it. i need to know which one of those plugs gives me a reading for the factory speedometer gauge.

i would also like to know which wires on the factory harness are for the speedometer and the trans temp sending unit.

 

The one on the tailshaft is the speedo.

 

the 4l60e has a tailshaft sensor. the 4l80 does not have a tailshaft sensor?
the 4l80 case is an early model and does not have the 20 way electrical connector port.

 

The output speed sensor is in the left hand side on the rear of the case.

 

thanks

 

thats what a meant sorry. rear of case