The holley 500cfm is used on alot of the toyotas that race the dirt tracks as far as i know. the #4412 carb is a 500cfm usually modified for racing. A typical 4412 500cfm two barrel with no modifications flows as advertised approx. 500cfm at 40.6 inches of water depression. As for the rpms I have never taken it above 6000. I run this setup in my 4x4 truck and rarely have it on pavement. I use it for rock and hill climbing, and mud racing. high rpms is a must beteen 3000 and 6000peak. I need a cam that could handle those rpms and engine modifications. thanx