Its 100% possible my numbers are wrong, I am no professional at using a flow bench. I can say they were consistently higher than my unported W2 Econo heads that flowed 268. What suprised me was .600 Lift was only 3.42 cfm better than .400 lift.
I’m mostly looking at the test pressure. Are you sure it at 10 inches and not higher? I’m not one of those guys who think every bench (even home built benches) should read wildly different. That’s why I’m asking. Do you correct for ambient temperature and barometric pressure?