i think he means a mk2 gte, cos i think the europeans call an astra gte mk2 a kadette GSi or something similar.
but this is just me guessingi dont know if the european GSis maybe came fitted with an 18se also, or only 18e?
do you mean a kadette-e gsi 1.8 when you say mk2? cos i think up to 1986 they were fitted with an 18e engine, the same as your mk1. the looms should also be the same if that is the case, cos if my memory serves me right (mind you its been a while since i seen under the bonnet of a 1.8 mk2 gte) the mk2 gte >86 was basically the same as a mk1, like the brake servo was on the wrong side n that.