I personally would never use PAC or any other beehive spring on an engine. After I had a coil break, you only have one for each valve, the damage is terrible. Take a look at conical valve springs if you want to save weight and not use exotics.
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.