Have 2002 altima v6 w215 55 R17 tires and wanted to know if you could substitute a regular compound tire in place of the speed rated tires which are specified by Nissan?

Yes. The speed rating simply means that the tires has been tested and is safe at certain speeds. As long as you do not plan on turning it into a race car that is fine. For more information on what the tire sizes and speed ratings mean see this article.

http://www.associatedcontent.com/article/513017/understanding_tire_sizes_for_your_vehicle.html?cat=27