hard steering

[fresnoron]

have a 30 Tudor. All new steering balls, Teflon easy steer buttons, shorter pitman arm, all new king pins and bushings, new tires. Steers easy with front wheels off the ground but really hard with tires sitting on ground. Checked the king pin thrust bearing is taking the weight of the car so am assuming that's not the problem. maybe have the tir rod and drag link adjusted too tight, not sure...any ideas what I can do...do they make a steering box upgrade or upgrade kit? scratching my head on this one. Thanks Ron