I figured the slop was in the steering geer. I adjusted the play so it only had about a inch or so free play. However, with the engine running the free play increased over a quarter turn.
Parts store/generic "remanufactured" junk, or a good box from the likes of Redhead (in Auburn, WA), or from Firm Feel or Steer & Gear? The latter two vendors make a speciality of increasing the road feel and self-centring action by installing stiffer reaction springs in the gearbox, which Redhead can likely also do.
Also that's good advice to carefully check for slop in your steering shaft to steering box coupler. Borgeson joints are fine, but so are un-worn-out, correctly-assembled factory-type couplers. Putting the shoes in rotated 90° from their correct position will cause steering slop.
And you'll want to make sure there's no lost or improper motion in the steering linkage under the car. If the idler arm (for example) wants to move up and down because it's worn or it's loose or its mount is wallowed out, that'll cause slop, too.
