I saw those classic industries ones before. It's impossible for them to fit! In 1970 the spring went to a 5 3/8" width. Thinking that I was wrong I checked Ames and they had the same listing. Called them up to verify and had them take a tape measure to the pad. It was 5 3/8" . I also had them check the spring and although he did not pull one off the shelf he agreed it was a 5" width (outer diameter)