I finally went to this list. The problem with the superhonda.com list is that it has the B18C engine code listed for the SiR beginning in 1995. This is true. There was a JDM SiR in 1995.

The B18C engine code in JDM refers to engines put in both SiR and ITR, even though the motors were not the same spec. In order to ascertain whether a JDM motor is an ITR spec motor, one looks at other indicators, like the number stamped on the head.

In USDM, we made life easier for motor factors by having a B18C1 engine code for the GS-R and a B18C5 engine code for the ITR.