Clarification for LS1 Limited Prep GT1 Motor Rules
#38516 from Daniel Speer · No action required · Minutes (2025-08 Fastrack)
Thank you for your letter. In answer to your questions:
1. Any mass-produced aftermarket intake manifold is permitted.
2. Intake manifold with 90mm OEM throttle body is permitted
3. Any mass-produced aftermarket cylinder heads is permitted with no valve angle modifications.