What is the title of this movie? Late 70's early 80's. A young boy is sent to live with his grandfather. The GF teaches him the indian customes to becoming a man. It also has something to do with guys stealing horses... help!

This question sounded familiar to me. I think it got answered a couple of years ago.

https://www.askmehelpdesk.com/movies/name-movie-268178.html

Could be Three Warriors.