I'm about ready to pull the trigger for a 2021 Silverado 1500 4WD CCSB with the 3.0 Diesel. I have the option for either a 3.23 or 3.42 axle. I ...

I'm about ready to pull the trigger for a 2021 Silverado 1500 4WD CCSB with the 3.0 Diesel. I have the option for either a 3.23 or 3.42 axle. I can find the towing capacity for the 3.23 at 9300#, but I can't find the capacity for the 3.42 axle. I doubt if there is significant difference in MPG but I'd like to know all info. before ordering.
BTW, GM just announced "employee pricing" for ordered trucks. Even if delivered after the end of the year.

If you plan to do any towing, I would go for the 3.42. It's not a huge difference, like you mentioned. It probably does not increase the actual towing capability, just makes it a little easier.

I should have looked a little closer at the "max towing" option on the "build" site. I selected the option and found that the 3.42 axle option is only available with the 5.3 or 6.2 engines. I'll ok with that. The 9500#, (2021 rating for the 3.0), will cover my use. Sorry for my lack of info. but maybe this will answer a question for another member.

Thanks for the follow-up.

Just reminder that the transmission and rear gearing should be evaluated in a combo. I once had a 5.3L/4-speed/3.23 combo that was a dog off the line. The newer trucks with that same ratio but more trans gears are a different story.

I also realize I have a pattern of putting bigger tires on my truck, so if I was buying new I’d probably want the highest ratio I could get.