Go Wing placement

Hello everyone and thanks in advance for any help that you can provide. My son and I are just finishing up a two year restoration of his dream 1974 Duster and we are getting ready to mount the Go Wing, after looking at hundreds of pictures we still can't figure out if the angled side of the wing goes to the front or rear, we have seen pics of it mounted both ways. Can anybody tell us the proper way?

Thanks again