I recently had Holley Marine Carbs that were giving me fits for my HP500's. I called and talked with Dean Gellner of Gellner Engineering who spent a great deal of time asking me questions about the problems I've been having. He truly cared about my problem and didn't try to rush me off the phone like most other shops I spoke too. He was very knowledgable and after our lengthy conversation I decided to send them to him. He kept in touch with me during this time and the turn around time was very prompt. I re-installed them on my motors and was really amazed by the smooth starting, idling and throttle response from them. I am convinced that Dean and Gellner Engineering are the kind of people we need in the boating industry because they care, are extremely knowledgable and are fantastic to deal with. So, if you love your boat like I do and want nothing but the best for it. Definitely give Gellner Engineering and Dean a Call and tell them. Darby Yohman (one satisfied customer sent ya!!!)