You are sort of in a catch 22 situation here. You don't know the flow numbers, so you don't know what you have, and you can't tell someone who is interested in buying them either. I would be hard pressed to buy a set of ported heads unless I personally knew the porter, or they were someone from a known shop. As for myself, I'm going with the TFS heads since I don't have anything, and by the time someone ports, or ships some of the alternative options, they actually cost more. My application is different though, as mine is a hot street effort, and altimate horsepower is not as important.