I couldn't find anywhere in the manual that says to allow for a break in period before towing. It does say something about driving conservatively for the first 300 miles. The "truck guy" (you know how that goes) at the dealership said it's not necessary. Regardless, I'm going to get it up to at least 500 miles this week before we tow.
It has the 3.73 gears and I'm aware that the 4.10 would be preferable for towing. It is almost impossible to find a 4.10 on a dealer lot and I got a decent deal so I didn't want to mess with ordering one. Also, I know everyone says to plan for the future trailers, but I can safely say we are not getting a new trailer any time soon and when we do, it will still be a travel trailer and not be much bigger than what we have now. No 5'ers until retirement which is well down the road.
I talked to someone who tows a 7,000 pound travel trailer with the 6.4 and 3.73 gears and he said it is a breeze.
Here is a link to the truck on the dealer website with the specs. It is a stock picture so ignore that. We paid 34K (before TTL) in case anyone is wondering. I got them down to 37K and they gave me 3K more than I owed on my trade. I also negotiated in 5 years of oil changes and tire rotations (maximum of 10 oil changes and 5 rotations) and tinting the front windows.
http://www.championcjdindiana.com/new/Ram/2014-Ram-2500-1f57d1fd0a0a00644872c496e622b147.htm