Think of the old style dragsters with the engine in front of the driver, the front axle was layed way back, kingpins were on a slant big time, this made them go down the track straight with little input from the driver. Your truck will be the same. If you have altered the ride height of the truck, your factory caster measurement will be off, add a few degrees if the toe in doesn't work. NAPA can get the shims for about $4.00 each. I added a few more degrees to my '37 and it made a ton of difference for the better. Just remember, the more you add, the harder it will turn when not moving.
Set your toe in to 1/8" in, or close to it, a little off won't make much difference as long as you are toed in. Right now you are looking for a difference in how it drives. The reason for toe-in is to take up the slack in any of the steering joints. Under driving conditions with all the drag and restance of the road and tires, your adjustment should be 0" in or out. Each joint has a little movement and together they should be add up to about one 1/8", yours may be more or less, thats why its trial and error. Joe
