Thanks for the info.I dont have an engine yet.My H35 is worn out and I'm trying to replace it. I almost bought an HS50 but it was tired as well. I wont look @ them anymore and I'll have to change my wanted ad here. I just happened to find this muffler in my old old stash of stuff. I really want an H35 or HS40,the H35 would line up with the tail pipe on my Columbia Rambler,I could modify the tail pipe for an HS40 using this muffler.Thanks again for the info.