well most 5.0s that I know have tunes and a few boltons. To put it in perspective, they gain nearly as much power as we do from a tune. I see plenty running 115-117mph traps.
The ZL1s are hit and miss, yes they are supercharged but they are extremely heavy and only barely faster than a stock 5.0. They also suffer from heatsoak REALLY bad so on the street they may be even slower.
'08 E90 w/ just boltons
'09 Z4 sDrive35i w/ just boltons