Champion irons flow numbers

205-210 cfm intake @.500-.550 lift, 155-160cfm ex. Depending on which flow bench and what they use to flow with. More than the engine will flow unless it's got enough to stay over 5500 rpm
My TTA heads were hand ported and went 206 on the intake with stock valves. The intake port is the same as a GN head.

The exhaust port on the TTA must be drastically better because mine went 196 cfm on the exhaust with the stock valves.