If you want to learn a bit about the settle but important differences between the 914-4, the 914-6 and 914-6 GT steel rear calipers, review some of these reference photos and notes starting here https://pbase.com/9146gt/image/154876306
More details to come...
Hi Brian, your report on the GT calipers is very interesting. You dealt with it very intensively. I am currently restoring a 914/6 and have several / 6 calipers. I have also found fine differences and I have a few questions. I hope you can help me. I would be happy if you would answer me. I send greetings from Germany, Andreas