Whether the past affects your current relationship depends on him- and you!
People’s behaviour is really not set in stone. It can change dramatically as they grow older & their priorities & values shift.
You have not said how long ago this behaviour was, what made him change, or how long ago the change was, or what his attitude to it is.
if he finds his past behaviour funny, or clever, or minimises it, if he is proud of it, I would be concerned. If he is still hanging out with the same group of people that he spent time with in those days, I would also be concerned (though this would depend a bit on what they’re like).
But if he knows he caused pain, and doesn’t belittle it, or see himself as the victim, I would take him as he is now. Don’t be blind to the reality of how he is now, but please don’t let the past colour that incorrectly!
My own partner is 60. Until late 30s he led his life in such a way (from what he’s admitted about it) that I really would not have wanted to be involved with him or even spend an evening with him. His life was about drugs & partying & sex- he had affairs & hung about with some pretty dodgy people. However when his first child was born he changed his life completely. He’s a different person and has been for many years- a loving, supportive, kind, faithful, reliable man (and a great father). I am immensely lucky to have him.
People can change. Look at what is in front of you, not what happened years ago.