whats this part??

WHAT YEAR is your car?

Some cars in the '70's had a smog control device part of the NOX controls I believe "on there" on the cable

Go here:

Download the '72 factory shop manual, which is free

http://www.forabodiesonly.com/mopar/showthread.php?p=1970088617

Then go to page 25-6 and read the section on NOx control on automatic transmissions