Standard tire on the '66 GS was a 7.75-14 redline (non-radial). My original spare is Uniroyal, but I am sure they used various makers, as they do today. I don't know about the '67's. Dan
In 67 it was a choice between whitewalls or redlines. I believe the cost was the same. Or you could order oversized tires?? Here is a clip from the sales manual for 67. Brand wise, I think just as Dan said, probably different brands were used. Hope this helps a little.
Thanks for the info jcamp thats a nice little pic you have there. I found the 7.75-14 and the F70-14 redlines in a firestone tire. Now for some "JK" wheels.