Front end shakes and bouncing??

Replaced the king pins,new steer tires,and new shockes.Could my leaf springs be bad and could this ruin my steer tires by making them have permanent wobble???truck has 900,000 miles on it.

 

The alignment was done but something is still wrong it could be a combo of things. The front end starts bouncing like its on a spring board. I can hit the throttle and make it stop but when I'm doing like 60 it starts really vibrating and the vibration will only go away with a change off speed.

 

All aluminum. I was reading on a couple forums about the KW W900 and a person had a problem with the bushings on the rear axles were worn and he could actually move the tires back and forth. I tried doing that and my bushings must be shot because I can move my tires back and forth like it was described. I have the AG 400 suspension hopefully that fixes my vibrating at 60-65 mph but I know that bouncing in the front will still be there. Almost same feeling as a warped tire and I know it's not thar because sometimes it rides perfect.

 

I replaced the u-joints about 5 moths ago. I really don't feel it so much in the steering wheel.

 

I wouldn't think the tires are out of balance with new good year steers but I will get them balanced again and maybe get centering lugs or those balancing plates( whatever they are called). Thanks for all the help everybody. Greatly appreciated !!! I'll post again after I get balanced and bushed.