Welcome to the board cheesey!!
Just because you have a 6.5 does not mean you have a GT. The 67 Cougar sales brochure indicates that the GT performance group included the 390 4V engine, (of course), the handling package, wide oval nylon-cord tires, low restriction dual exhaust, power front disk brakes, power booster fan (or clutch fan), low restriction air filter, special 6" rim wheels and had the GT badge instead of the 6.5 one. I am not sure if the VIN would confirm the GT but the Marti report certainly would. And the 6.5 was available as a stand-alone option in 67. Hope this helps...should be the same for the 68.