I spent thousands of dollars trying to improve the towing capability of my truck. New rear end gears, more cooling, better brakes on the truck and trailer. Upgrades to the engine...it helped a little. Then I decided to buy a bigger truck. The difference in towing with a truck that has more than enough capacity versus one that just barely has enough capacity is unbelievable.
I feel much safer, hills are no problem going up or coming down. I no longer am worried about towing, it's a breeze.