Pretty easy buddy, im doing the same with a GT shell atm, put a N/a engine in it and using a EP85 ancillary loom i had, that plugged into the existing GT fusebox. There will be a few ways to do this just like turboing a N/a. The EP91 might be slightly different, i dont know if the ancillary loom disconnects from the fusebox like a EP82 does ? Worst case is fit a EP91 N/a full bay loom in the Glanza, use one from the same year for ease ie 97 loom in a 97 shell. The alternator, starter etc all use the same plugs. You need a N/a MAP sensor and ignition setup, the thermostat housing sensors may be slightly different depending on the year of the engine. And obviously a N/a ECU.