It sounds like talking to him might not be the greatest idea, from what I can get, it sounds like the biggest advantage you'd get from talking to him is closure. Simply closure. If you really feel that you should talk to him, feel that talking to him is the only way to get some closure on your situation, then talk to him. However, from the sounds of things, it sounds like you're not interested to talk to him, but simply feel, almost obligated, to talk to him. Let me tell you there is no obligation to talk to him, if you're fine not talking to him, I really think not talking to him would be the best idea.
Also you don't have to call your current father your "current father" or "step dad", that man is your real father, both legally and ethically. You may not have his genetics, but he has influenced you and shaped you strongly, in a way that your biological father did not do. Just remember that.
Hope it goes well!