[The Fixer]

Iron-head LT1s had 10:1, and aluminum head LT1s had 10.5:1, but it's a good chamber design and fuel-injected, with a knock sensor to retard timing if it does start knocking. Really, it depends on a lot of variables (like quench, chamber design) but generally you can go that high on the street safely with 93 octane, a knock sensor, and a good tune. It can be done with a carb too, but will definitely take some experimenting and plenty of tuning.