I use Castrol Hypo C 80W-90 without any issue. I have used Redline 75w90 NS in past in my first Pantera and it made the ZF leak fluid after sometime. I recommend Castrol.
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.