3500 single axle or 2500? Any difference?

A GM 3500 will have an extra leaf spring in the rear spring pack. It will also have slightly wider wheels and larger tires than a 2500HD.
In the diesel trucks that's the only difference. Since your talking gas trucks then the rear axle is different. The 2500HD will have the 10.5" AAM axle and the 3500 will have the larger, stronger 11.5" AAM.

I used to run a 2005 2500HD regular cab with a steel dump insert. The 2500 does have the smaller 10.5" ring gear but is still rated at 10K by the axle manufacturer. I used Timbrens to level the truck. At the time the limiting factor was the tires and wheels. With the 1000 lb. insert installed I could carry 2800 in the bed without exceeding any ratings. On a few short hauls it handled over 4K without issues. If I had wanted to carry more weight on a regular basis I could have swapped over to 19.5" Rickson wheels and tires. As others have mentioned, drivetrain components are the same. So for your application I'd say to get a 3500 if you can, but with just a few mods a 2500HD will do the same job.

With a gas GM, there is a substantial difference. GM puts a semi floating rear axle on the gas 3/4 ton truck as opposed to a full floating rear axle on the 3500. The semi floating does have a markedly lower axle rating.

Buying new,it makes sense to just get the 3500.

As mentioned by Spoon, there are more differences these days then there used to be.
Given the minor price difference, get the 3500. You wont be sorry!

spoon059 wrote:
With a gas GM, there is a substantial difference. GM puts a semi floating rear axle on the gas 3/4 ton truck as opposed to a full floating rear axle on the 3500. The semi floating does have a markedly lower axle rating.

Buying new,it makes sense to just get the 3500.

I don't believe that to be the case after about 2002 or whenever they got rid of the non HD 2500 and 1500hd. Got a pile of newer 2500 GM gasses at work and they sure look like AAM axles under them. Quick parts search revealed the same.

If I'm mistaken please show for me and the rest of us on here.

And for those that say "get a 3500 they're only a few bucks more". Have you ever truck shopped, new or used? 2500s outnumber 3500s by a HUGE margin and a 3500 gasser, unless it's a work truck, and even then is pretty much a unicorn. When a 2500 with more springs is the same truck.

The 2500HD does not have a semi floater...... it has a full floater... ask me I have one. The standard 2000-2007 2500 and 1500HD had the semi floater with 9.5 Axel, yep had ones as well. So the difference on the 2007.5 and up is only the spring pack and rear diff goes from 10.5 to 11.5. Wheels are the same, tires are rated different. The 6.0 will serve u well.

Spoon is quite wrong in his statement about axles.

The only trucks since 2000 that do not have full floating axles were the 2500(non hd) and the 1500hd. Both of those trucks are quite rare. All 2500HD and 3500 trucks since 2000 have the full floating axles and are quite similar.

I bought an early 2015 3500HD SRW 6.0 that I had built for me. It had an option for different GVW's. It maxed at 10,500 if I recall which was what I ordered. Maybe the axles are different depending on how it is speced. I never cared to investigate it at the time.

So at the risk of the weight cops arresting me, lol, yes a newer GM 2500hd is the same as a 3500 minus some spring capacity.
Dime a dozen 2500s vs unicorn 3500s, I'd take advantage of the selection and negotiating power of the multitudes of 2500s.

Thanks for all the responses! When you guys talk about rear axles and such, are all the newer ones built with the 4.10 rear ends , or 3.73 (on both the 2500HD AND 3500HDS)? My 2007 classic GMC has the 4.10s, and I wouldn't want to step back into the 3.73.