If you are really running 11 to 1 on 92 swill with iron heads you are either very good or very lucky. That cr is usually about where you start topping out with aluminum heads which is one reason (more cr capability) to go from iron to aluminum. I built my motor (Stealth heads) to be a true 10.0 to 1 cr. I wasn't going with a big cam and wanted a healthy street motor that can even run regular if it has to.