the engine will be fine towing that much weight, without a tow package your truck lacks a trans cooler, so i would be much more concerned about your transmission than your engine beig too small. i'm not a huge fan of the bumper mount hitches but as long as you don't have a body lift the one you have purchased will work. keep in mind you will need a brake controller for that large of a load too....

 

I pull a 28 ft with a 5 ft V-nose w/ 2-136" and 2-151" deep snow sleds and a 'sno-scoot', but then again i have a 3/4 ton w/ a 6 speed.
I think the more important question would be 'where' you plan on towing to. I pull from 3100ft elevation to 6500ft in 30 miles so the climb is pretty good, i can pull at any speed over any pass, i took the trailer to Biloxi after Katrina full of clothes and supplies, truck and trailer was 20K rolling down the road, and still got 12.5 average over 6K miles.
So it depends on what you have to pull over and how often, i know it's nice to have an exhaust brake on the long downhills!

K

 

Read your owner's manual. It will tell you how much you can tow. Anybody who disagrees with the numbers listed in there is wrong and an idiot. Period. Dodge doesn't want all the warranty claims associated with bad towing advice. I have never understood all these morons who say you need the top engine offering and top towing package and a 4x4 to do any kind of serious towing. With the lesser engine, it will be slower, that's all. The bumper hitch on the non tow package trucks has an enormous steel bar bolted to the frame to support the weight. And a 4x4 always has a LOWER payload/tow capacity due to the extra weight. Idiots.

Also, you don't have to get the tow package to get the trans cooler. My non tow pack 4.7 has a separate trans cooler and oil cooler. The tow package just has a heavy duty one.

 

On my 07 it looked like it just had a bumper insert but when you got under it you saw that it was really a class III hitch that was hidden under the bumper if thats any help.

 

You can get a good Reese hitch @ Walmart for a good price. I would look into the 7 pin harness from the dealer so that you can install trailer brakes if the trailer has them.
5500lbs is fine for the 4.7L.