11.0:1 On pump Gas (91 92 93 or 94? E85 definitely will), If you put the right cam in it. Look at it this way. Let's say you build it with 11.0:1 and it pings, so you drop the timing back to 30 degrees to get rid of the ping. You lost way more than you would gain if you would have lowered the compression ratio to 10.0:1 and ran 36 degrees timing.
Or you just end up having to mix race fuel to cover it up. I'm not saying it is not possible, just giving you some worst case scenarios that many people run into.
Good luck with your build.