Difference between 2003 2500 and 2500HD Silverado

In 2003 they made a 2500 and 2500HD Silverado. What are the differences?

My 1st thought is that the HD comes with the Duramax.

The 2500 had no diesel option and it was basically a replacement for the no longer existent 1500HD

There is a few differences between the two mostly being with the frame. First of all the 2500hd sits about 2" taller out of the factory vs the 2500LD. The rear frame section of the 2500 gets narrower from right above the rear axle to the back of the frame. The 2500hds frame is the same all the way back.
Also the 2500 has a GVWR of 8600lbs, which is the same as a 1500HD, and uses a semi-floating rear axle, while the 2500hd has a full-floating rear end and a GVWR of 9200lbs.
The 2500LD and 1500HD are basically the same trucks except for the fact that the 2500LD is available in crew or extended cab while 1500HD was only available in crew cab models.

On the rear axles, I thought only the 3500HD came with the 14 bolt FF, I was pretty sure the 2500HD comes with the 14 bolt SF

I stand corrected... 2500HD comes with 14B FF, 8.1L and DMAX come with AAM 11.5 (pure beef)