543

It’s not really a mystery about what it takes to run a certain ET/Speed at a given weight.

Just use an on line calculator.
Plug in the weight, speed/ET, weather info, track elevation, etc...... it’ll spit out a number.
That number is the minimum that you need for uncorrected power as the car sits on the starting line.

I’m not saying by any means it’s the last word for what a set of Indy heads will flow, but the only Indy head I’ve tested that touched the 400cfm range was a set of their 572-13 cnc385’s with 2.350 intake valves.