One of the main advantages of quench is the turbulance it creates in the mixture, effectively forcing it towards the flame front, which also helps cool the chamber. As a result, you can run higher compression that will actually detonate less then a somewhat lower compression engine without quench.

However, quenching a sl6 might indeed create compression too high for present gasses. So, if one could find a piston that has enough compression height (positive deck) to reach up into the (unmilled) head, and has an offset dish of the right size to drop compression enough, I think it would work. But...does anyone make such a piston, or does one exist that could be modified with a dish?