Air FLow Research
http://www.airflowresearch.com/
They just hit the Ford market,but have been doing Chevy stuff for years (around thirty). In any event World Products has some good stuff (I had originallly planned to go with the big Windsor aluminum heads from them but I saw an ad for AFR and checked out the data on them. I was impressed by the flow. the same as the World Products heads but with a 15cc smaller port. However Westech has flowed the AFR's at about 20 cfm less (still 260 cfm though like the big Windsor heads your looking at, just with a 185 cc intake port vs. 200 cc) Anyway I don't see where you could go wrong with the Roush Windsors. 260 cfm is still good for something like 550 hp. Where you want to compare heads is all the way through lift points. Peak flow is handy but if a head flows better at the low and mid lift points (with the same or smaller intake port) the head is gonna have more average HP & TQ. and indicates a more efficent design.
See this is why you talk to the experts
Sim Engine
750 cfm carb
AFR 185cc heads
Dual Plane Intake
1-3/4 Long tubes
10:1 comp
HP: 478 @ 6000 rpm (vs 470)
TQ: 463 @ 4500 rpm (vs 465)
Bit more HP but only a loss of 2 ft/lbs. of torque. I haven't compared both cams through the whole RPM range but I'm pretty sure they made a better suggestion