The USga website has a database for conforming and non conforming clubs, regarding the new groove rule but they do not list older model clubs. Are old irons with v grooves conforming for condition of competition?
Good question. I believe that any clubs with v grooves are conforming. I play some old Hogan Apex Redlines from 1988, and I believe they have square grooves. I've never been able to determine if they are legal, but I presume not.