SB vs BB who wins?

With basic off the shelf non trick heads like trick flows sbm 190 vs bbm 240/270 the sbm gonna be in the 500s hp with pump gas and street strip cam and the bbm 600-700 hp.

And torque the a larger piston has more surface area for the combustion pressure to apply force to and be multiple by crank and since most the force is applied in the top half of the stroke the force is gonna have more time per stroke on the shorter stoke but will have less multiplying effect.

So at the very least they have similar torque capability but I'd give the bbm the slight advantage.

But the advantage is the bbm has large bore for large valves, larger structure for larger ports to be able to spin the similar torque to higher rpms for more hp, at 5252 rpm tq and hp is the same above hp is always more Eg.. 6565 rpm hp is a 125% of torque and 7878 rpm is 150% and 9191 rpm is 175%. etc.

The breathing available to the big block should smoke the small block.

Think of a 400 b engine as a mini pro stock engine with a 4.34-4.4 instead of a 4.7 bore but with similar stroke.