I kinda of thought that the 60 would not fit. I had to add a spacer to the firewall to get the OS50 to fit. That engine is going to come out since it once again has some kind of ring or bearing problem (this os 50 has been nothing but trouble) I just purchased another os56SF off of the "bay" that I am going to replace the 50 with. As I said before a good ball bearing 46-50 would be plenty for this plane. Good Luck with yours!