The b16a1 produces [email protected] rpm. The differences between b16a2 and b16a1 are: in the diameter of the throttle body (bigger on the A2 engine), the mapping in the ECU and the increase of the compression. That is where the extra hp and torque are coming from. I'm not sure about the cams. And of course the writing on the cam cover is different. On b16a1 the DOHC letters are bigger then the VTEC on b16a2 is the opposite.