What size truck?
How do you determine whether you'd need a Ram 2500, for example, or a 3500? Is there a weight cutoff for the 2500?
Forum Discussion
If buying new, just get the 3500 and don't look back. The price difference is pretty small (at least mine was back in the day). Even if you don't need the extra capacity now, you will thank yourself down the road when you do.
