David,
As noted, the Taurus motors work great. I did this mod and am just your average level mechanical ability. I detailed the process on my site. You can see the steps involved. It is easy to do on a weekend in one day.
http://markscars.ca/Pantera_Projects_2.html
Mark
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.