will stock struts from a 99-04 GT fit on a stock 98 GT? I thought they were the same from 94-04, is this correct?

 

The struts have been the same since the days of the Fox. So yes, they'll fit w/o a problem.

 

79-93 struts are only for use on lowered 94-04's and any 79-93. The earlier struts are 1/2 inch shorter which returns some bump travel in lowered cars before you tap the bumpstop.

EDIT: This thread belongs in suspension.