If you are using stock wheels and close to stock size tires the alignment specs will not change. If, however, you are using wheels with a significantly different offset or some kind of bizarro size tire the spec may change and will have to be custom set. From the discription of the wear pattern of you current tires it sounds like you do need an alignment. Are your driving habits rough? Lots of bad roads? Well, I would suggest having an alignment with new tire installation using factory settings......hope this helps.