Is there any sense in my confessing to a crime many years after it happened?

I would say it doesn't make any sense to confess the crime itself, as that would just get yourself into trouble. However if you have a lot of resent, remorse, or just pent up feelings because of it it would be best to release that someway other than getting yourself into trouble. Maybe talk to somebody you trust, talk to yourself, or do whatever you feel is necessary to relieve you of that stress that it's causing/caused.