We are a dealer for the Blue thunder heads but like Barry said they are hard to get and you have to buy them when they make them. We can order what you want and waite and see when we will get them. On the heads you want you do not say what bore size or what valve sioze you want to run. The Medium Riser heads will max out at about 380 cfm and that is with a race style valve job and at least a 2.25 intake valve. We have done the Blue Thunder High Riser head with a 2.25 valves that flowed a little over 400 cfms on our 1020 bench on a 4.310 bore fixture. If you are not running more than .700 lift you need to look at the flow at .400 to .650 lift and not worry about the max flow at .800 or .900 which will do you no good. We do some stuff over .900 lift and then we look more at the .500 to .900 flow numbers. Just a lot more to it tham flow as well when it comes to the heads. Good luck, Keith Craft
