For years I used Indy rockers. They lasted 3 to 4 years, I had a 283 degree .68" lift solid roller. Then I switched to Ersons, really nice rockers and the price was reasonable, unfortunately they donät make them anymore. However, still have them in the engine. Then I decided to try T&D's, for some reason they didn't work in our engine. since they work in many others, I don't think it was because of the design, jsut some "glimps" we didn't catch. After the third major valvetrain failure I buried the T&D's and ordered a set of Harlan Sharps as spare. Hope they'll do their job when the day comes.