need help IDing speedometer piece and advice

That's the speed sensor that worked in conjunction with the emissions "N95" package on some 71' cars.

Below is a quote from daredevil's post in here......http://www.forabodiesonly.com/mopar/archive/index.php/t-131739.html


"In 1971 the ECS & CAS systems were used in the other 49 states, while California cars went to the NOX system in addition to ECS & CAS. The NOX system includes special components for the transmission, a special camshaft with more valve overlap, and a 185 degree thermostat. There were 2 different setups available depending on manual or auto trans.

Manual trans = a switch on the trans sensed what gear the car was in. any gear below high gear made a solenoid cut off the vacuum from the carb to the distributor vacuum advance unless the temperature sensor indicated the underhood temp was less than 70 degrees.

Auto trans = similar to above, but used a speed sensing switch inline with the speedometer cable."