Not even all that, man.
You need to consider the tongue weight in the rear, you need to consider the load on the tires - 1500's came with P-metric tires - you're going to need an LT tire, load range C at minimum. Rear suspension as CP noted, also rear brakes, better proportioning system, the works...
I say it's the perfect excuse for a new truck. For as much as you love the truck you have, you'll love a new one better. That's why cars are better than women - they don't get mad at you when you leave 'em for someone else, and you don't have to leave 'em with half of your stuff...
Jeff
I forgot to mention I got rid of the P tires and replaced them with either 8 or 10 ply truck tires. I cannot rember which ones I have. I also installed off road shocks and I use an equilizer hitch. Even in a high wind I have no sway problems.