For 96, like you said, there's 2engine codes, the D16Y7 and D16Y8. The EX came with the stronger engine w/ VTEC, the D16Y8.
Later (97 I think) the HX came out with the D16Y5 (VTEC-E) and on 99 and 00, the Si coupe came out with the B16A2 (DOHC VTEC). Even though the Si is an EJ8 (EX) on steroids, the chassis code is EM1 rather than EJ8, despite some cosmetic differences.