I had them on my 98 350, but I really can't remember if I saw a difference ( had so many things done to it at one time) . Has anyone been able to see a diff at the dyno or track? I have the Volant Air system and HPP111. I can tell a small diff, I think it is the Volant more than the programmer. <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" />