During the GMC Syclone and Typhoon production, there were a number of conversion trucks that were modified by GM/PAS or an outside third party. These trucks are considered to be conversions as most all were randomly selected from the standard production run of trucks.
Both the Syclone and Typhoon had conversions done with the Syclone having more known variants. Many conversions were modification of the exterior, mainly with paint or additional graphics added. A few trucks did get extreme makeovers with extensive paint and body modifications.
The most notable of these conversions are the ten GMC Syclone Marlboro Editions due to its publicity with being part of the Phillip Morris Marlboro sweepstakes giveaway. Not all of the conversions where over the top with graphic and body modifications such as the Marlboro or the PPG Syclone. Some trucks had a more subtle approach such as the the Saudi Syclone and Typhoon. These trucks were modified in order to meet the limited availability of premium fuels in the middle east. They also received a swapped gauge cluster that read in metric instead of standard measurements.
While the GMC Syclone and Typhoon were used for conversions, to date there are no known production Sonoma GTs that received any official conversion by GM, PAS or an outside company.
- 1991 GMC Marlboro Syclone Edition
- 1991 PPG Syclone Pace Truck
- 1991 GMC Saudi Syclone
- 1991 GMC Indy Syclone
- LeRoys Customs GMC Syclone
- Saudi Typhoon Info
- 1992 Indy Typhoon Info
- Geiger Typhoon Info