[Damien]

3,775 lbs for a '78 c10 long box fleetside with a V8 according to Chevrolet Pickups 1973 to 1998 by John Gunnell. The book says a '77 is 3,973 lbs, but does not say what engine and lists a 6.5 ft fleetside box under the 131.5 inch wheel base. The book also does not list whether or not the truck has A/C or duel fuel tanks. The extra 200 lbs could come from those items.