Great oil comparison by the ZO6 track guys. 5W30 Pennzoil Ultra, API SM synthetic, Best wear protection and 280* before onset of thermal breakdown. It'll be what we put in ours at the 10K point.
0W40 vs 5W30 vs 0W30 - Corvette Forum
0W40 vs 5W30 vs 0W30 - Corvette Forum