Handeling on my F250

I have an 2003 F250 supercrew with a 7.3 diesel 4x4. I have had it in for an engine replacement once. ever since I have had nothing but problems. I had to take the truck to a dealership to have all the cab mount bolts replaced. now the steering seems to be acting funny.

it seems slow, heavy, and sluggish. when counter steering in snow this is an extreme issue since I cannot keep up with the steering and will spin out.

also at highway speeds it seems to wonder in the lane like the wieght is off the frontend, or I have a flat rear tire.

I have taken it in to other dealerships, but non have found anything.

Have you checked the tire pressure and compared it to the placard on the truck?