Re: Steering Stabilizers
Nice truck! I've got an '85 K20, 4" lift and 33's.
You should have a steering stabilizer - it will help. With 35's you could run with duals. Might be a little stiff. We've run singles with 35's before, no problems. Should solve your problem - you could convert to x-over steering... but you shouldn't have to, if you've corrected your steering linkage geometry.
The pulling to the left is another problem. Wheel bearing, brakes sticking/caliper, ball joints, or a tire problem, pressure, balance or structural.