Advice on a 2004 dodge Ram 1500 truck towing capacity

Also, the tires are ready to be changed, and I was also wondering about what I had heard re: changing the tire size for some type of improvement? Any truth to this, and if so, what might be the most advisable change?
Sorry if my lack of experience is appalling...we have just come off of living the last 10yrs aboard our sailboat, so this is going to be a bit of learning curve in some areas.
Many thanks again for your patience, advice, and suggestions.
All the best
Bob