Today, the NMRA Tech Committee finalized the 2021 Limited Street class rules with a clarification on clutches.
That clarification is as follows:
CLUTCH, FLWHEEL & FLYWHEEL SHIELD
- "Long Style" Clutches are permitted and restricted to a minimum of 10-inch single disc.
- Steel or aluminum hat permitted.
- Any single, dual, or triple diaphragm clutch is permitted.
- Titanium or exotic materials in the clutch assembly are prohibited.
- Clutch and flywheel must meet SFI Spec 1.1 or 1.2.
- Steel flywheel shield meeting SFI Spec 6.1 is mandatory.
- Flywheel shield cannot be modified for clutch adjustment and/or cooling holes.
- 2005 and up Mustangs are allowed to retro-fit to the 79 -04 factory style cable mechanism.