We recently started a new project, marrying a 2009 sts and a 64 cadillac. We are using the entire drivetrain, including the front and rear sub-frames, the floors and inner rockers as well as the firewall and frame rails. We then cut out the floors and fire wall out of the 64. We stretched the sts 6.5 inches before the fire wall and 6 inches just in front of the rear wheel house. We reinforced the inner rockers and mounted under the 64. We can now retain the entire interior including the dashboard in our northstar powered 64 Cadillac Convertable. check out our facebook for build photos and progress. we will be sitting on the subframes next week.