Paguy,
Do you have any other implements such as a box blade or cutter? I found that some stock top links don't cut it for all your implements. Since you're going to buy a top link, I'd suggest doing the following with any of your implements.
Hook one up (such as your ballast box) to your lower links. Then measure the distance from the tractor top link connection to the implement top link connection. If possible, do this with your other implements. If possible, measure the in the position you plan to use the implement.
For example, with your ballast box, measure it lifted up in the position you plan to carry it. You can lift up via the lift pins and use a pry bar on the back and some wood blocks to level it at the height you plan to carry it. Write down that measurement. Then with the box blade, let it sit on the ground (where you would use it) and measure that distance. Do this with all your implements if you can, etc.
You can get an average distance that way.
That distance should be close to the mid point or mid length of your top link. In other words, the middle of the retracted and extended length. Most top links tell you what the retracted and extended lengths are, so you can add them up and divide by 2 to get that point.
That way you have the ability to adjust it in (shorter) or out (longer) an equal distance to level your implement in either direction...to tilt it forward or backward equal distance in the position you plan to use it.
It may take a little longer to do it, but it sure beats finding out your top link is too long or too short just before you want to use it.
