The 3/4 ton does use a longer brace due to the frame being narrower. Dave
You are correct. I should check before typing incorrect info. I just looked at the FAM and there's quite a bit of difference in width.
Goach2, I wouldn't run very long without a brace on the rear of the fenders. Unsupported they'll just flap in the breeze and probably crack from the flexing. A piece of perforated flat stock you can get at the hardware store steel rack would be better than nothing.