Towing with a 1500 classic

[drywalldan]

I'm looking to get a used Ram 1500 for a 5000 lb camper can i tow it with a321 gears should I use a truck with 321 gears and a 5.7

 

[crash68]

If there's a 5.7 under the hood, towing a 5K trailer won't be a problem, 3.92 would be nicer to have especially if you decide to get a bigger/heavier down the road.
You could always regear your 3.6 truck to 3.55 if you don't plan to go much heavier on the trailer.