GT Performance has been a leader in the high performance marine industry for over 20 years. Located in Upland CA, GT Performance provides a wide variety of marine services. From your basic service to full restoration and upgrades. GT Performance Engineering has a staff of highly trained Mercury Certified technicians that are among the best in the industry. They are able to fix any type of powerboating issue using the latest state-of-the-art computer diagnostic equipment. Our goal is to keep our customers satisfied and their vessel running at optimum performance.GT Performance offers 20 hour and 100 hour preventive maintenance services and highly recommends having your boat serviced annually.Proper maintenance is crucial to the life of your boat and if properly maintained, you could eliminate unwanted and costly repair work. We are also an authorized Mercury parts dealer and service center. GT Performance recently built two 1650HP engines for Greg Olson's 33 Daytona. It was no surprise when Greg became King of the Desert at Lake Havasu's Desert Storm Shootout. GT Performance is now an official Donzi dealer, if you are interested in purchasing a new Donzi check out your many options on our website. We also know everyone wants to go a little faster yet have the comfort of reliability. That is why we have taken our technology and made sure you receive real power that you can count on. Our engine packages are designed to meet your horse power needs. Visit our website for a full list of options available. GT Performance Custom Billet Aluminum products are currently available. From alternator mounting brackets to Power steering reservoirs, our products are designed to be reliable with a clean custom look. When your ready to make some changes under the hatch give our parts department a call @ (909)982-8391. You can also find more information on our website about all services offered. We look forward to doing business with you soon!