D-max ain�t grunting with 6500 lb travel trailer!

By grunting I don't mean struggling lol. I guess another way of saying that is "mean sounding"

You're mostly correct but because of so many option levels, mid year changes, and customer custom ordered espcially on work trucks we don't go by the thinking that this is the only way they come. It's best to know what they have by looking up the vehicle build on our special GM website. When we order parts for vehicles we don't tell the parts guy what gear ratio we need or what color a part is. We tell them what we need like a "ring and pinion" or a "door panel" and give them the last 8 of the VIN. They then look up the parts by that vehicles build sheet and give us the part it was built with.

If you want to know what your vehicle was really built with call your local GM dealer parts department and ask them. They will need the last 8 numbers of your VIN to look it up.

redchevy is correct. Every 2500 or 3500 with a duramax (since 2001) will have 3.73's. In this unique case it is very cut and dry. There were no mid year changes, no custom ordering for a different ratio, nothing other than the buyer changing them after purchase.

The only exception in regards to the Duramax would be the Kodiac (top kick?) medium duty trucks. I believe they were available with 4.56 or were all 4.56 not sure.

I pulled up the 8 that where at the dealer the OP said... 3 of them list 4.10 gears and a 6.0 L gas v-8.

You can even get on Chevy's "Build And Price." As soon as you add the Duramax in the truck, it takes away your 4.10's and adds 3.73's.

Wonder why GM doesn't allow 4.10's on the Duramax..?

Because you don't need extra torque. It would just be a useless gas mileage hit.

3.73 = 6.6L Duramax Diesel
4.10 = 6.0L Gas

Nice to hear so much positivity on the duramax. Never owned one but always wanted one. i have the 5.3 and was thinking about upgrading to the duramax but constantly hear ppl dogging it. too many powerstroke guys with too many opinions i guess!

Honestly think you would be hard pressed to go wrong with any of them these days, they are all solid trucks. Ours have always been good. Most people are just brand groupies and don't know much about anything.