a bunch. L series datsun motors are the reason i have faith in the 4ac. the l16 is a counter flow 1.6 four that made 96 to 109 hp stock. the sixes make all sorts of power. they are/ were popular with racers, so there has been plenty of r&d for them. Hell, I have an entire book on building them as race engines.
I can't imagine that the balance is quite the same thought...