i just would like to know what needs attention on these heads? i understand they need the standard "blueprint"..ck valve job,guides/stems clearance,straightness, installed height,proper springs for cam,maybe backcut the valves?,...but is there any other things besides pushrods?....and the most of all how is the stock and ported stealth airflow vs 906.+.ported 906 big valves! actual numbers,and or hp increases please...i cant be the only one interested. not really interested in ede's...looking for stock look.