Chief, if there was a way to make these heads work on this motor I'd sure like to know how. I went from a 406 with cleaned up 16 heads, a 226/226 cam with lots of overlap, long branch mans and tons of low end torque to that same 406 with ported round port Edelbrocks that flow 300cfm @.600, a 230/230 roller cam and Doug's headers and my low end tanked. So much so that I'm seriously considering go back to the iron heads and just cam it up a bit and save the heads for a bigger motor.