The way I see it neither the B16A2 nor the B18B have a large advantage over the other. The B18B does have a torque advantage, but that is slightly offset by its longer gearing. Also the B18B lacks the oil distribution for high RPM operation. The B16A2 has equipment meant for a high RPM redline, but people don't call it the "torqueless wonder" for nothing. The lack of torque is slightly helped by the shorter gearing, but it's not going to throw you back into your seat. The B18B is a cheaper engine generally speaking, so you probably could do more with it for the same amount of money as a B16A2.