SB vs BB who wins?

Ok so this is one I've been pondering for a bit. Just to preface, it's purely an academic exercise to see if I can learn something.

So, take a stroker SB of choice. Call it a 408. Could be 390, or 416. Now take a 383/400/or 413. No stroker big blocks, that's not in the spirit of the experiment.

Top these engines off with a decent set of heads. Nothing wild and exotic, but a good set of well prepped heads your typical dude might run. Appropriate and fairly equivalent supporting valvetrain, intake, exhaust, compression etc.

Which series engine would better, in terms of power and torque production, and why?
Here is a REAL LIFE test to help answer your question:
My friend, Justmoparjoe, had a 408 with aftermarket heads in his cuda and ran 7.2's at best in the 1/8. He went to the 400, stock crank, with aftermarket heads and went 6.8's if I remember correctly (could have been 6.7's)???
So, the 400 gave up cubic inches to the small block and ran faster. Same car, same gears.