Wide tires have more rubber on the ground at one time then more narrow tires have, making them harder to turn. Wheels with a smaller backspacing move the tires away from the centerline of the truck, requiring more effort to make them turn. Taller tires with more profile have more sidewall flex the shorter sidewall tires. They don't necessarily turn harder, but it takes longer for the turn to take effect. Your "bigger tires" could have all 3 things going for them, which all effect the truck turning experience in a negative way. Depending on how carried away you got, it may well be something you have to live with.

Modern trucks are built closer to the weight and height load requirements then trucks of the past were built to. Older trucks tended to be overbuilt, so there was an extra margin of safety, but the modern trucks often have a higher capacity then even the over build of the older trucks. One only needs to look at the max capacities to understand that todays trucks are expected to carry more weight.

All that said, even back in the late 70s and early 80s, bigger tires on trucks caused a lot of problems. Wheel bearings, and cracks around the steering box mounting on the frames were pretty common issues associated with mounting larger tires on a truck then it was built to use.

Oversized tires exceed what your truck was designed to have and use. How far oversized did you go?