it's up to, depending on your idea of streetable you might be asking too with this 50/50
396 500 = 1.26 hp per cid with a peak hp around 6000 rpm , 600 = 1.52 hp per cid with a peak hp around 6500 rpm. For a weekend burnout machine probably streetable enough but seems like your going for a more balanced sport/super car pro touring thing.
What about and centrifugal blower?
Your best bet is to build higher efficient engine power more like 1.3 to 1.4 lbs-ft per cid than the more standard fair 1.2 to 1.29 lbs-ft. Which your should find a good builder and work on a game plan together. Higher lbs-ft will make the power at a low rpm for a given hp and cid.