JDM engines have more HP because they run higher compression than their USDM counterparts. A B16A2 is a USDM motor, the B16A with no number is the JDM version, but watch out there are a few versions of it... The XSI (OBD-I from an Integra), the SiR-I (OBD-0 from a Civic usually mated with a cable tranny) and the SiR-II (OBD-I from a Civic with the hydro tranny).
My suggestion would be to grab the SiR-II JDM complete changeover from
Specializing in JDM-USDM Engines & Parts...hmotorsonline.com That way you'd be sure you're getting the right one, for a decent price, and with fast shipping from my experience... and with the changeover you'll get the correct shift linkage and axles, plus the ECU.
The
problem, however, is that with the JDM you'll have to run higher octane gasoline, preferably 93 if you can get it in your locale. But I'm not positive, you may have to run premium with the USDM variants too, even with the lower compression. Also, JDM motors have fewer emissions controls, so if you have strict smog laws, you'll want the USDM counterpart.
Another thing that I ran into with my swap (D15B7 to B16A as a matter of fact) is that you'll need either an aftermarket bracket for the stock one or a new throttle cable from a 99-00 SI I believe, and also radiator hoses from the 99-00 SI or a Del Sol VTEC.
