Your engine code is d16y8. I'm sure of it. If you want to find out for sure just take a look at the engine block just to the left of the header. There's a little flat spot there with the engine code stamped on it.
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.
The Si (EM1) also sports an even shorter shifting S4C transmission, with a different shift knob (wow!). I think it may have a larger fuel tank. Some of the suspension components are also different, most notably the sway bar mounts for the front and the rear. The seats have different covers, and the headrests have holes in em. They came in 3 colors instead of the 5 that were offered to the other models (most notably the popular EBP). And if I'm not missing anything else, the rims were different, as were the tyres.
thats cool....I was going to get an Si when I got my civic....but all the ones I could find had been driven like dogs...like...a 99 or a 2000 with 85k-100k on the clock...and were either totally riced out...or in crappy condition! My ex was MINT when I got it...bone stock granny driven with 40k on the clock