Hmm, I think this limitation is only the case with the ZL1 and not with the standard SS. While it took some practice I can now get to a 1.82 60' with only NT555Rs. And I think I can do better once my tune gets sorted out.
No nose dives, but some bogs, and spinouts, along with one smelly clutch run.
I think Chevy is protecting the ZL1 drive train. Is it any stouter than the standard SS?