How strong can a fully grown gorilla be?

I have to ask what type of lift you are asking. Is this a deadlift, a military press, or a 1,000 lb "budge"? Two of the three should be possible for a gorilla. Depending on the rules, the human record deadlift is near/somewhat over 1,000 pounds. A gorilla is considerably stronger than a human, though experiences none of the conditioning of a weightlifter. A "budge" of the weight would be easy, i.e lift it at all. The human backlift record is over 2 tons. A military style press (over the head) might be too difficult. Gorillas are not fully upright and thus the spinal column could not stack vertically to support the weight. In effect it would be carrying a massive weight at a lean. I doubt if a gorilla could lift this.