Two plug Dist vs. Single plug unit
I'm in the middle of putting a JDM B18C into a 96 EJ and ran into the same thing. I guess the older (or JDM perhaps) Integra's used two plugs at the dist. instead of one. I own a 99 GSR and it has the single plug. I looked at the wiring in my Helms manuals and the pin-outs are the same, Honda just combined the two into one it appears. I'm going to have to chop and solder but that easy enough. The only other item of contention is the IAB wiring. I've read where I can use the EVAP purge wires and just move them to the proper pin at the ECU, change the plug and re-lace the wires to get it to reach the solenoid.
I hope this "helps" (or at least explains).