Actually now that I think back I've been asked a fair amount over the years at feed stores and horse happenings if my truck had 3.73 or 4.10s. When I say 4.10s I can remember at least twice guys saying at least YOU GOT a real pulling machine" Honestly I got tired of not having enough truck to hook and pull just about whatever and twice before I bought trucks with 3.55 gears.I know what the 2nd genners say OH I pull THIS much weight with NO issues etc.But I sure had issues with 3.55s.Towed anything over 6k like crap in my humble opinion.Yea they towed but on anything but flat roads, hills always was a go fast down hill and floor it going uphill.Got tiring on long trips.So I wanted 4.10s when I bought.I very seldom check or worry about fuel mileage.I bought this truck to PULL and that it does very well.A buddy of mine with a 05 dually and 3.73s is always going on bout how much better my truck pulls without having to tow at 70 plus mph to keep the steam up.

 

What's wrong with towing at 70 to 80?

 

I had 410s on my 03 and went to 373s on my 06. Like the 373s better and get better mileage. I would stay away from the 410s and add air bags.

 

Towing max 70 mph is fine.75 up its dangerous and to more then your self.I stay around 68 mph.Air bags don't help it tow more or easier.Just ride level.Theres a REASON 4.10s are a option.

 

I agree with this. If it wasn't safe to tow at 75 there would be no speed limits that fast. Only here is Cali do they make you go 55 if you have anything behind you. Rediculous!!!!

 

So back to the original post,

The only difference is the added spring sounds like, and the pay load of course ??

Both have the gear options ??

 

Are your trailer tires rated for 70-80?

Most aren't rated for more than 65.

 

Yes same trucks only spring differance.Yes on gearing.Same trucks again.Oh but COMMON SENSE tells me towing at hi speeds is dangerous.I could care about the posted speed limint.

 

and for the difference between 4;10 AND 373 FUEL MILAGE.

I just keep the rpm's between 16 @ 1850 and my mileage has not changed, just my top end speed.

 

Towing at 80 is irresponsible, you are risking other peoples lives...

Yes, added spring is the big difference between the 3500 and 2500.