From what I remember the HD models have the black plastic fender flares on the front and their hood is slightly different, it bulges up higher than a 1500, of course the wheels and suspension and bed, I'm actually going to make a work truck of some kind so I may use the modelhaus utility bed or I'm seriously thinking about waiting until the wrecker that revell is releasing comes out and mixing the 2 kits and making a 99 3500 wrecker out of it.
I also want to mix the wrecker kit or utility bed with the AMT 93 F-150 to make an F-350 too.