I've had an '81 Z28 since I was 19. It came stock with 350/350 and 3.08 gears. It weighs pretty close to 3600 pounds. Base coupes were a few hundred pounds lighter and Berlinettas were in between.
Advance Design 1/2 ton pickups weigh approx. 3100 lbs. Suburbans: 3600 +-, 3/4 ton pickups: 3480 +-
Weights vary slightly from year to year.