Lately we have noticed it depends where on the lake we get them and what they have been feeding on. But I think you can average a nice fat well proportioned gator at 11 feet to be around 300-400 lbs.
Largest gator (not on record) in Florida weighed 880lbs. 13' 11 3/4" long.
Gator on record, weighed 800lbs and was 14' 5/8" long.
We got a few who's heads were huge, bodies were medium and visa-versa.