The Marriott gauge is a wonderful effort. However, I am amazed that so many people still think the Manson gauge is hard to use and inaccurate. Some continue to think it cannot be used in the horizontal position. The horizontal position is the simplest and most accurate method by far. Some still think that rod flex is a problem with the Manson. It is not. I have explained in plain language, in past threads, how to use the Manson gauge, yet many seem to ignore the simple instructions, mine, not Brownell's. I guess I could make a video, but it would affect Jon Hosford's business, and I don't want to do that.