Be sure the sector gear preload is adjusted properly, either by the spring scale method on the steering wheel suggested in the shop manual, or by going for a 10 inch/lb. increase in turning torque at the steering shaft nut in the center of the steering wheel as I've been doing for almost 60 years. Also be sure the wheels are pointed straight ahead when the steering gear is centered, which they should be if the drag link is straight and in good condition and the steering arm at the LF wheel the drag link attaches to at the front isn't bent. Most wandering problems are caused by a sloppy steering gear preload, although the huge oversized tires (and probably incorrect wheel offset) are mistakes that can't be corrected with wheel alignment.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!