Lots of good info,
http://camaros.org/
1st Gen 68's are hard to decode, as not much on the cowl or vin for 68'
Much can be added that was not original...........I have looked at many cars and added documentation to the above site
Unless you find the build sheet under the seat or on top of the gas tank.......a few holes here and there can help but its wide open
Go on a test drive and run the dog shit out of it, I always do