Coilovers/?

[j.fro]

To check the front suspension components, jack up the front end and give each wheel a good shake. There should be no play at all. With both front wheels in the air and the steering wheel unlocked (key on but car NOT running), you should be able to move the front wheels through the entire turning arc. There should be a little resistance, and it should be uniform through the arc.
Check the tie rod ends to be sure that the lock nuts are tight.
Because you've experienced the problem with both sets of wheels, my guess is going to be alignment. Does the car pull to one side or the other at highway speeds? If the toe is very different from one side to the other it could cause this problem...and going to a larger diameter wheel may be exacerbating it. Did you have heavy wear on the inside edge of only one of your old tires?