Let this go, or send the teacher a venom filled email telling him exactly how I feel?
A couple of notes:
1. People who are bullies like this don't think about their impact. It's likely he won't even remember you. The schools have gotten stricter about what can and cannot happen legally in schools, so it was what is was at the time. And if he does remember you, he may still be adamant about his views. So be prepared for not being remembered and for him not caring or even calling you out on it.
2. Ask yourself this: what are you expecting to have happen? This is an important question, because when you've been on the receiving end of something you're not happy about, it can stick with you for a really long time. The problem is, you're going to verbally attack this guy for something that happened nearly 30 years ago. If he does remember and if he has overcome the traits that you perceive make him act like a bully, then maybe he'll say sorry. And then what? Otherwise, you'll have told him off, and then...?
It might help to write this stuff down in a journal, or send an email to yourself to work through the issue. And also put a timeline on it - write down the possible outcomes of contacting him, and then how you would feel afterward, a month after, a year after. Someone exposed you to something you didn't agree with and it left a psychological scar on you, so you have to deal with it somehow. Sometimes all you need is to write things out to get a clearer picture, because if you keep it in your head all the time, it goes nowhere.
Honestly, I think everyone has to go through something like this growing up. For some people, it's worse than others, and for some it's physical and some it's mental. I had two friends in college who were dating. We had no idea the guy was unstable because when they broke up, he hung himself and left a nastygram for her. She was pretty messed up for a long time and had a really hard time dating after that.
I kind of think that's part of becoming an adult - you have something serious happen to you and you realize it's not all fun & games. Someone you know dies, your parents split up, you're involved in an accident, someone bullies you, etc. I don't think I know anyone who didn't have some kind of physical or emotionally traumatizing experience growing up, but if it's bothering you this much after all these years, then it's definitely time to try something else to make it go away. Beating the guy up won't fix it because he's still going to be the person he is, so you have to find a way to deal with it on your end instead.