compression ratio on pump gas

Quench isn't something you just throw together and go. It has to be measured and actually blueprinted. In other words, parts have to be modified accross the board to acheive proper quench. Since you're talking about measurements in thousandths of an inch, each cylinder will be a little different and need to be addressed accordingly. It's not cheap. If it's not in your budget, you'd be better off building the lower compression motor. If you simply try to sling a motor together you think is quench, you might end up with a useless motor that will only run well on race gas.