Tango, yes there are other combos that would work too. It's just that the #11 fills the bill at 9.15:1 so that you could run junk pump gas with the aluminum heads and tight squish and the fact that it makes max torque at 3,500 rpm's. To my way of thinkin', it's the ultimate street-friendly motor.

Scooter, you'd be down 100 ft/lbs or more with camel hump heads. In my opinion, GO BIG OR GO HOME. Look at some of the other combos using different heads. No comparison to the superiority of the AFR heads.