Richard,
While you've got them open, you might look into this mod that Dave Bell did to get a few more hp.
http://www.spacecitypanteras.com/Technical/Gutting_the_GTS_Exhaust.htm
John
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.