Highest flowing sbm heads?

Mean416 said
My goal would be a 600+ hp 4" stroker based engine that I can take to the strip occasionally and mostly be obnoxious with around town.

I figure in round numbers I probably need upwards of 310-320 CFM to get to those power levels on a fairly optimized tune and combo. Just from the research I've done. Some guys here have actually done it and I'm appreciative of their knowledge and advice.

That is exactly what I am building. A 440. 4" stroke 4.185 bore. running victor heads, putting a built A-500 behind it this spring but adding a built 8hp70 down the road. maybe nos and hoping to add a Torque Storm down the road. Throwing it in my 67 Cuda street car. Should be competent enough.