Of course this is no guarantee, but that same rudder in my '89 was an exact fit, requiring no modification whatsoever. I used loc-tite on the set screw that holds the rudder in, since it's just that and the tiller arm clamp that hold it into the boat. The rest of the installation was quick and easy, except for laying on the floor of the boat and reaching in under the gas tank, but that's just a little uncomfortable, not complicated. No leaks, and the boat steers like brand new.
Good luck, it should be pretty straightforward.