The frostbite style grapples have an easily removed plate that spans the two lower tines (see picture). That allows you to pinch, and pick up rocks the size of softballs (depending on operator skill

). In the picture, the top clamshell is contacting the lower plate in it's current orientation. A camera mounted to the grapple makes it much easier to see what you are doing.
Or it can be removed to make the tines dig in easier. I leave my plate on pretty much all of the time as I've had no problem getting under rocks and popping them out with it on, and it makes it easy to get the smaller ones out.
I have a similar sized tractor (LS XR4145) with a loader with max lift capacity of 2,700 lbs at full height. With the grapple I've never been worried about twisting the loader. The tines are spaced close enough it's almost a non-issue (I imagine if you tried to pick up a massive rock so it's cantilevered out on one end, you could run into problems).
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