Well you have to get the wheel straight FIRST
Now, there is "stuff" what happens...............Custom steering wheels don't have master splines, and sometimes guys grind off the master splines because they could not figure out a problem, AND you can assemble the steering coupler 1/2 turn off, which puts your wheel exactly upside down, everything else being "right"
1...Center the box. At close to center look for the master spline on the box. With the column in the car and either connected or not to the steering box, with the steering wheel properly oriented and centered, the box spline should line right up, or very close. A fraction of a turn.
With that done, the tie rods should be nearly equal. Is it possible you just THINK the wheels are straight? you cannot really tell without a big straightedge, or actually driving the car, and this is AFTER you align the front end
Is it possible on or more of the tie rods / ends are off "something else?" That is, are they actually the same in pairs?
Is this something that "has changed?" In other words, is something bent / broken /rusted in the front end?
Now, if it's a matter of the toe is correct, the front tires are straight, and the steering wheel is cocked, all you need do in that case is simply "walk" the tie rod assy's equal amounts until the wheel centers, then recheck / reset the toe