i think 430 to 450 rwh is very possible on a stock block , however i have seen engines go at 400. its all in the tune of the chip.

i went with a 6lb pulley, diablo chip, cai, and spark plugs denso and am around 405 rwh and i will be close to 425 to 435 when my blower is returned from porting.

i will have the same amount of boost as a 8lb blower pulley will give.

i believe the single blade throttle body will not give you that much improvement the money may be better spent on other mods.

just my 2cents