You know I can’t answer that because I had an old chrome craftsman timing light for 30 years that worked on everything I ever tried it on including this MSD set up. The reason I have a new one as I had to buy a timing light while I was on this trip stuck in Charlotte I didn’t expect to do timing while I was on the trip. So that’s why I have this new one The theory is the MSD box throws out three sparks each time under 3000 RPM and I have made videos that prove that so they say that confuses some timing lights I have not personally experienced that but I’ve heard that many times
