Jethro, do you have new shock absorbers, wheels and tires on your truck?
Installing those three things made a night and day difference in how my truck handles at all speeds. I can let go of the wheel at 60mph on a freeway and the truck tracks straight as a die. If your white knuckle experience is due to wandering or jumping around, I'd suggest looking at those three things (assuming your steering gear and linkage isn't worn out).
