When SC went to the COTF I was surprised the amount of freedoms they allowed. Control everything apart from engine would have been my call.
Control Dampers, Spring set, bar set. And control chassis built by supplier. No engineering uprights or any other suspension components. Fit your engine and tune with the toys provided by the class. Save your money
what am I talking about it's motor racing. Someone will build a faster split pin than you've got.