"Anybody have any tips on using a disc. Wasn't quite sure about the top link. Should you extend it as much as you can to have the rear disc dig in as well? What about going through dips and uneven ground? Don't won't to break the back of my tractor."
With 3pts, if you're simply looking to plow a piece of ground or field and maintain it level, then you keep the front and back gangs level with one another while engaged. Whatever depth you want to cut, figure it by watching the furrow (the path you leave behind the plow) and making sure you aren't ridging or wallowing. If you're ridging, leaving a hump of plowed dirt in the middle of your passes, then your back gangs are digging too deep and bring too much soil back toward the center of the plow. Vice versa, if your scalloping out your passes your front gangs are too deep and tossing more soil out than your rear gangs can bring back to the center.
Uneven ground and 3pt discs aren't good friends. If you know how to constantly adjust for the ridge or hump or shallow you're working then you can adjust on the fly. If not you will have to cross-work the ground.
You won't break the "back" of your tractor by which I take it to mean the 3pt top mounting. The top link should and would fail long before you break the cast housing it's mounted to.
PM me DCRC. I wish we were closer and I'd drive on out and do what I could.....