That is part of the vent tube . It is pressed into the case from the opposite side from the "bullet" that sticks up from the top of the case above the diff.
Ron
PANTERA INTERNATIONAL
A DE TOMASO CAR CLUB
Presents the De Tomaso Forums
The On-Line Meeting Place for De Tomaso Owners and Enthusiasts From Around the World
Clicking on the banner will take you to the sponsor's website.