Ram has built a number of 1500s, 5.7 hemi's with the new 8spd trans. Some or most of them have the 3.21 gears. The tow rating is about 2,000lbs less than the same truck with 3.55s regardless if the tr...
The final ratios on the 8 spd look pretty good. But I would want to know more about why the difference in ratings between the packages. I don't know much about RAM, but with Chevy, the 3.42 gears often come with a heavier transmission cooler, engine oil cooler, etc. It isn't just the gears, but the whole package that bumps up the tow ratings over the standard equipment.
The ratios may be fine, but if you don't have anything to cool the transmission, you can get into trouble just the same.