The bed width was the same on the 1 1/2 ton single rear wheel, & dual rear wheel pickups. Jim Carter owns a 1946 Chevrolet 1 1/2 ton dual rear wheel pickup. It can be seen in the "working trucks" section of his website. Ernest Holmes model 490, 515,& 525 medium duty Wreckers used the wider dual wheel fenders on their wrecker service bodies. They also used narrow single rear wheel fenders on the larger wider service bodies of the Heavy Duty W35, & W45 wrecker service bodies. I've seen the wider fenders used several times on these "W" model wreckers with over half of the fender under the body. Holmes used these fenders up until 1956, when the more modern platform style service body was introduced. Check out my webshots album of "Spankys Antique Wreckers" for examples of both style fenders. link below.
