I don't think the factory supplied bed lifts, so it is likely aftermarket. My 50 Chevy COE, model 5700 has an aftermarket grain bed with an aftermarket lift. The truck weighs 7450 lbs, as that lift is massive. Factory literature will tell you the cab and chassis weight but to get an accurate weight you will have to get it on a scale.
Kent

1937 Chevy 1/2 ton
1942 Chevy 1/2 ton
1947 Diamond T Model 509
1951 Chevy 1/2 ton
1950 Chevy COE Model 5700 ~ "Barney" ~ And more pix