There are several different 1.6 pulleys with different offsets FYI
It`s the offset of the pulleys. I think (but don`t know) that each generation (mk1 2 3) has a different offset. I know when I was putting together my mom`s 84 Jetta I scared myself pretty good when I put on a pulley and it was hitting the pump mount. I found another pulley in the pile and it fit perfectly.
Yeah that's very possible considering it was an AAZ engine with a 1.6 pump on it...