All 90-93 RS/LS/GS engines are B18A1's. There was no B18A in the Japanese domestic market, all of theirs came either with a SOHC ZC or a B16A (RSi, XSi.)

To tell the year, look at the casting date on the head. Mid '89 to early '91 casting dates are 90-91's, mid-91 to early '93 are 92-93's.

Whatever that brace is, cut it off. That guy is an idiot.