Here we produce mechanical speedometer conversion kits for GM 4L60E, 4L65E, 4L70E, 4L75E, 4L80E, 4L85E, and T-56 six speed transmissions. We have been building these kits for over 15 years and have accumulated a long, happy list of customers over the years. The kits are easy to install, come with instructions, and best of all they work! When upgrading your car to a 4L75E or 4L80E these kits make it easy, and you can use your original dash! If you have any questions, or if you cannot find what you are looking for, just send us a message and we will be happy to help you out.