The dump body appears to be an 8'- 4yd with a full cab shield. Assuming that this is a 10ga. body with an underbody hoist of approx 7'x15" then I would make an educated guesstimate (SWAG) that it weights about 2300 lbs +/-. add 450-500 more if 8ga. construction.
Very cool old Chevy, I love it.