The adjusting screw pointing toward the exhaust manifold needs to be tightened until the slack is eliminated, then turned slightly further until there is approximately a 10 inch/lb. increase in turning torque at the steering wheel nut as the box passes over the center point. That extra preload is probably what the "1/4 turn" bovine scatology from the seller is referring to. That is how all worm and sector steering gears are adjusted, regardless of the manufacturer. (At least since the first one I worked on in 1960 was done) It was on a 1949 Dodge.
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!