I think it depends on the power level your after, 350 hp and lower small would be easy choice, 350-450 hp you could go either way 450 hp plus I be definitely thinking big block especially in a street car.
More then horsepower level its what you intend to do with the car. My racing days are behind me and I mostly attend cruise nights now. My 354 Hemi certainly isn't high horsepower, engine builder estimates around 435 hp, so it makes plenty for what I need and no small block is going to get the looks my Dart gets. Currently on the lookout for a gen 2 Hemi, so yeah, Id go for the BB.
