Between 3600 and 3700 lbs.
Around 4100-4300 lbs depending on bodystyle
I have a 1990 Caprice Classic Brougham LS. Manufacture sticker says Gross vehicle weight is 5045 lbs.
This information is located on the inside of the driver side dorr jam.
The last caprice's weight in around 4100-4200 lbs. The 77-79's weight in at 3500-3800 depending on 4 or 2 door. Don't confuse curb weight with GVWR. One is for the car, one is the most the car can...
It should weigh somewhere around 575 pounds. Most Chevy small blocks that are all iron should be close to this, give or take a few pounds.