It surprises me that dealers end up installing stock replacement clutches with 500hp engines. It is true that a 2400 lb Cobra isn't as hard on a clutch as a 5000 lb vehicle, but you still need to select a clutch accordingly. I see 550hp SBF's paired with King Cobra clutch kits (300-350hp kits at best) or 500hp big blocks running NAPA clutches. It just doesn't work and owners end up going back and redoing the whole clutch assembly.