You may need to unhook the the drag link to center the steering wheel and gear box. What you are looking for is the true center of the gear box, and to see if the steering wheel is bolted on in the correct spot. The steering wheel should be splined and only fit one way, but you never know what can happen in the life of a truck.
Once you have true center of the gear box, tie the wheel in place with rope or the seat belt to keep from turning it. Hook up the draglink and check the spindle arm for center over the axle. The joint where the draglink and spindle join should be centered on the axle when looking down from the top. All straight axles are set up this way. Its a easy check to see if the right parts are installed.
With only two tie-rods theres really no adjustment that can change the way the wheels turn. A modern car or truck with four tie-rods can be adjusted to center a wheel, but not two!
You are on the right path with the draglink, just don't try and make a adjustable one, steering is one of the items you don't want to mess with for safty reasons. Joe
