Ok, here's the deal on old solid axle 4x4s. You'll actually have 2 adjustments, one for total toe (tie rod) and one for steer ahead (drag link). When doing an alignment on one of these solid axle type frontends, first the total toe is set to spec using the tie rod adjusters. Then the steering wheel is centered using the adjuster on the drag link. This is assuming that the pitman arm had been correctly installed on the box. Most '67 and later 4x4s have both adjustments.
If you're needing to replace the drag link with the adjustable type, you might be able to use Moog #s ES2027L, ES362S, and ES2026R to make an adjustable link. These part #s are for a '71-'72 model year truck.
Napa alos has a listing for this part http://www.napaonline.com/masterpages/NOLMaster.aspx?PageId=470&LineCode=RPC&PartNumber=27769&Description=Drag+Linkhttp://partimages2.genpt.com/partimages/246392.jpg
