If you can manage to find a 90 - 91 Gran Pix GTP, some of those had a turbo charged 3.1. Youd need the manifolds and intake ducting and the ECM I think. Then youd have to do some other custom work to set up the oil, vacuum, and coolant lines for the turbo. DO NOT use a used turbo though. Thats asking for trouble. Go to
www.60degreev6.com They may be able to help a little more.