Lee
Hello & Welcome to the Forum!

The GG1 is a beautiful locomotive and one I would like to own myself.
The drawback for me is the 20 inch length and the necessary 072 curves to run it on.
I don't believe there is anything you can do to modify it run on the 060 or lesser radius curves.
You could  remove the front & rear trucks, then it might run on the lesser curves.
Whether you could pull a consist with it and have it stay on the track would be another question.

The other option is to purchase an RMT version of the GG1 which is 14 inches long and will run on 036 curves.

Happy Rails.
Dave