iron heads for a 408?

The numbers a flow bench generates are entirely the result of the math and correction factors and the operator. If you cannot get the numbers the other kid's dad can, but you are confident your equipment is clean, sealed, and the calculations are correct for your weather/altitude, you have to belive the numbers it gives you. (it's a garbage in, garbge out...deal) That's why we never "race" flow benches. I know guys with poor calculations based on poor weather instruments, that get really good numbers...and the engine never makes what the head result says it should. The truest result is the engine on a stand or in a car going downt the track. Anything else is like looking at a thermometer reading to see if it's cloudy outside. As far as the numbers..244 is enough to support more than 500hp with the right cam. I think BJR's program doesnt assume past 100% efficiency. It might, I'm not real familiar with them in general...lol. So feel free to correct me Billy, but the numbers you list show a smaller cc, and a cfm figure that is just as you said: unattainable at least at 28". The basic thought process I use is the smallest valve and port cc that will get the cfm at 28" I want. Also remeber, the intake port extends from the back of teh intake valve, to the base of the carburetor. It's not just the head port. Anyway, roughly double the cfm is what most engines can basically do horsepower wise, assuming around 100-105% efficiency at peak torque. I know of street engines that are 108-112% efficient at peak torque. Efficiency is a factor of a lot of variables and is an empirical value resulting from testing. Not just number plugging into an algorithm like most cam and head spec'ing type programs. A head with 240cfm @ 28", flowed by a guy that knows his bench, and has good weather info, will make 480hp with a moderate (240-250 @ .050 cam. IMO, you're fine. BTW, that's a good number for Magnum castings and the 1.92 valve.... nice work.