I may be wrong, but I thought they stopped making the 1.6 in 1985, when they changed the body style, so I would presume that yours is the 1.8. You could check the owner's manual, or find the serial number, which the parts store might be able to use to determine the engine size. You could also check your Haynes book, they usually have a section on all the different engines available, and how to identify them.
Mine was a GL sedan with front wheel drive, and the 1.8 was the standard engine for that model.
I just checked our book, they do have a number in there for engine identification. Your were right ty :)