Whats different?

Do both have 4L80E tranny?
Does the 1500HD have the smaller 5.8ft bed?

What else is different?

Thanks, John

I'll answer part of my own question. In 2005 GMC did not offer a Light Duty 2500 only 1500HD trucks. The 1500HD trucks did have the standard short bed of 6.6 ft. I also think in 2004 GM did not offer 1500HD but did offer 2500LD. In 2003 I think they offered 1500HDs and did not offer 2500LDs. All of which in the model line up above offered Quadrasteer.

I am still not positive about the transmission for the years that offered 1500HD or 2500HD for both 2wd and 4x4. I think that the tranny is a 4L80E but I'm not 100%. Anyone know for sure?

I know my 2005 is a 4L80E

2500(LD)'s are 1500HD's made in 2004. No other differances.

Do both have the 4L80E transmission?

Basically does your truck have the 4L80E tranny?

Yes, all 1500HD and 2500LD trucks are equiped with a 4L80E. For some reason, GM feels necessary to call a 2500LD Crew Cab Truck a 1500HD. You can get a 2500LD in different configurations, such as extra cab, but the 1500HD is only offered in the Crew Cab. In 2004, GM had a brain fart and droped the 1500HD designation for the Crew Cabs, calling them a 2500 for that one year only. Who knows why they do what they do.

Regardless, all had the same engine (LQ4 6.0)
All had the same tranny (4L80E)
All had the same rear end (14bolt, except the QS version with the D60)
None have the 5'8" bed.

I never understood why GM did this. It doesn't make sense. This leads me to belive the decision was driven by the marketing department!

Another thing that doesn't make sense to me is why they introduced a 3 chassis at all. Why not just make a light duty and a heavy duty frame? The 1500HD/2500LD frame is the same as the 2500HD/3500 frame from the front bumper all the way to the rear axel, where it morphs into the small frame. I don't know why it is like that.