I know the 240 and 270 heads flow identical from.100" to .300" and then start to change. It isn't until .600" you really see some substantial increases for the 270's vs 240's.

I'm going to investigate getting the stealth's ported with new springs, locks and retainers and see how much i'll be into them compared to if I sold them and bought some trickflows. I'm thinking I'll end up having the same total amount of money in a set of heads either way even if I take a few hundred dollar hit on the stealth's.

That is a interesting thought on the about the cross section to cubic inch ratio. I'm not engine builder and do not know science to building an engine but that makes sense to me at face value. I'm sure there is more to this!

AndyF would you have dyno sheets you could post showing the 240's vs 270's when you did the back to back pulls? It would be interesting to see the slower port velocity of the 270's down low in the rpm's and to also see where peak torque and hp happened for each head. I am surprised the engine didn't make more hp on average earlier and at a greater number since you had some pretty serious lift without a ton of duration on that cam. Like I said I'm not a engine builder so that may seem like a dumb statement! It is the air velocity that is keeping power so close to with each head correct?

ProSport - That is a impressive run! What weight is your car and what trans setup are you running and what is your tire size? Please divulge any more details you can on your ride if you can! Wicked car!