They are $38 at
https://sfifoundation.com/drag-racing-chassis/And there are many to choose from
DRAGSTERS
SFI Spec 2.1C Rear Engine Dragster (Top Alcohol/Methanol) – 5.99 Seconds & Quicker
Effective Date: December 3, 2021
SFI Spec 2.2D Front Engine Dragster – 5.99 Seconds & Quicker
Effective Date: December 3, 2021
SFI Spec 2.3U Rear Engine Dragster (Top Fuel) – 4.99 Seconds & Quicker
Effective Date: May 7, 2021
SFI Spec 2.4D Front Engine Dragster – 6.00 to 7.49 Seconds
Effective Date: December 3, 2021
SFI Spec 2.5E Rear Engine Dragster – 6.00 to 7.49 Seconds
Effective Date: December 3, 2021
SFI Spec 2.6C Front Engine Dragster – 7.50 Seconds & Slower
Effective Date: December 3, 2021
SFI Spec 2.7E Rear Engine Dragster – 7.50 Seconds & Slower
Effective Date: December 3, 2021
FUNNY CARS, ALTEREDS AND ROADSTERS
SFI Spec 10.1G Funny Car Roll Cage (Alcohol, Advanced ET, Nostalgia, etc.)
Effective Date: December 3, 2021
SFI Spec 10.2A Altered Car Roll Cage – 6.00 to 7.49 Seconds
Effective Date: December 3, 2021
SFI Spec 10.3B Altered and Funny Car Roll Cage – 7.50 Seconds & Slower
Effective Date: December 3, 2021
SFI Spec 10.4B Side Steer Roadster Roll Cage – 7.50 Seconds & Slower
Effective Date: December 3, 2021
SFI Spec 10.5A Nitro Fuel Funny Car Chassis – 4.99 Seconds & Quicker
Effective Date: October 31, 2013 (edited Oct. 1, 2014)
FULL BODIED CARS
SFI Spec 25.1K Full Bodied Car Tube Chassis – 7.49 Seconds & Quicker; 2,800 lbs. Maximum
Effective Date: July 2, 2021
SFI Spec 25.2E Full Bodied Car Tube Chassis – 6.00 to 7.49 Seconds ET; 3,200 lbs. Maximum
Effective Date: July 2, 2021
SFI Spec 25.3D Full Bodied Car with Aftermarket Body Shell and Tube Frame, OEM Body Shell and OEM Frame with OEM or Modified Floorpan and Firewall, or Uni-Body with OEM or
Modified Floorpan and Firewall Roll Cage – 6.50 to 7.49 Seconds ET; 3,600 lbs. Maximum
Effective Date: July 2, 2021
SFI Spec 25.4D Full Bodied Car Tube Chassis – 7.50 to 8.49 Seconds; 3,600 lbs. Maximum
Effective Date: July 2, 2021
SFI Spec 25.5E Full Bodied Car Stock or Modified/OEM Floorpan and Firewall with OEM Frame or Uni-Body Construction – 7.50 to 8.49 Seconds; 3,600 lbs. Maximum
Effective Date: July 2, 2021
SFI Spec 25.6A Full Bodied Car Stock / Truck or Modified/OEM Floorpan and Firewall with OEM Frame or Uni-Body Construction – 7.99 to 8.49 Seconds; 5,000 lbs. Maximum
Effective Date: July 2, 2021