Jim, my 630 hydraulics won't squeal with a super heavy bale, but the front end might come off of the ground, ha. My neighbors feed tractor broke down, and I fed hay with my 630 for him for a month. Heaviest bales I ever messed with. He had a real gentle rise into his feed area, and I had to either tie the bale to the spear, or back up to the feeders. Those bales were supposed to weigh 2000 lbs, but I never had the chance to weigh one. I had a 45 loader on the 630, but I refused to try to haul one on the loader. They weren't designed for a load like that. Of course, the three point wasn't designed for it either. Who had heard of a 2000 lb bale in 1960.
I can stick the same bale with my 50 - same results - nose in the air. I think the 60 should lift a 1500 lb bale, but would pick the front end if not on level ground.