The International Syclone Typhoon Registry (ISTR) is a non-profit organization that is focused on the accurate history, preservation, technical information and data collection of the 1991-93 GMC Syclone, Typhoon, & Sonoma GT sportmachine trucks. ISTR offers an exclusive online source of news and data that is regularly updated with new information and latest events via our forum and website. ISTR is dedicated to the exchange of related information, parts, ideas and mutual interest in the ownership and enthusiasm of the SyTySoGT trucks.

ISTR was formed to help not only share the history of our beloved trucks, but to help maintain a community who is focused on the continued preservation of these unique and rare production trucks. As we continue to grow and expand this website, we plan to offer many more features and opportunities to our community and members that share the same passion and enthusiasm in SyTySoGT ownership. This is not an overnight project and only with the help of both individuals and a community as a whole, will be able to expand and reach the high standards we have set forth to be the best source for SyTySoGT information.

We hope you enjoy the information presented on this website and welcome you to help contribute to the information. As we grow in membership and support, we plan to add features for the members and contributors who support making this place the best source of SyTySoGT information. We currently have some projects underway and will be releasing more information as it becomes available. We are excited to share ISTR with all SyTySoGT owners and enthusiasts and look forward to expanding our knowledge and data with our unique trucks.


If you would like to make a direct donation to ISTR, please use the button below. Direct donations help such things as; operating costs, expanding ISTR with both technology based improvements and membership benefits, event sponsorships, and help pay for acquiring and release previously unreleased data.

Donate to ISTR


Interested in advertising or becoming a sponsor on ISTR? Contact advertise@sytyregistry.com
ISTR is a non-profit organization operated by owners and enthusiasts of the SyTySGT. Information provided on this site is a combined effort of years of research and efforts of individuals who have put forth the time to acquire accurate information and data on these unique trucks.  If you would like to make a donation towards ISTR and help continue to make this information available on this site, please click here.