My concern would be why it cracked. If it was me I don't think I would even move the car if I thought the ring gear bolts could of caused this to happen. Regardless the whole transaxle most likely will have to be removed to weld it up.
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.