Lift capacity is a function of the tractor weight, counter weight, hydraulic capacity, and lift point. If you're using forks, you will be able to lift less weight at the end of the forks than if you had something at the back of the bucket. Lift height also makes a difference as leverage changes throughout the lift. Some max loads, I can lift to about 75% height and can rev the motor to get it the rest of the way, but I can hear the detent activating.
I have a B9200 with BF350 FEL and I'm just about maxxed out around 800lbs....which for a tractor weighing around 2000lbs is pretty impressive. Wish it was more. However I need to move up to an L series machine to increase my weight, and even then a L3200 only lifts like 1200lbs if I recall...