G3 tegs are rounded and the G2's are squared, a conversion would look like ass and the lines would not flow well at all.
Now if you took the front end of a 3rd Gen JDM integra and grafted it to a G2 teg while keeping the G2 fenders so that the body lines are kept intact, and swapped the front end of the hood and bumpers to match the headlights and get everything lined up as it should; That my friend is a conversion worth doing.